/usr/share/doc/postfix/html/postconf.5.html is in postfix-doc 3.3.0-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
4971
4972
4973
4974
4975
4976
4977
4978
4979
4980
4981
4982
4983
4984
4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
5045
5046
5047
5048
5049
5050
5051
5052
5053
5054
5055
5056
5057
5058
5059
5060
5061
5062
5063
5064
5065
5066
5067
5068
5069
5070
5071
5072
5073
5074
5075
5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
5097
5098
5099
5100
5101
5102
5103
5104
5105
5106
5107
5108
5109
5110
5111
5112
5113
5114
5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
5129
5130
5131
5132
5133
5134
5135
5136
5137
5138
5139
5140
5141
5142
5143
5144
5145
5146
5147
5148
5149
5150
5151
5152
5153
5154
5155
5156
5157
5158
5159
5160
5161
5162
5163
5164
5165
5166
5167
5168
5169
5170
5171
5172
5173
5174
5175
5176
5177
5178
5179
5180
5181
5182
5183
5184
5185
5186
5187
5188
5189
5190
5191
5192
5193
5194
5195
5196
5197
5198
5199
5200
5201
5202
5203
5204
5205
5206
5207
5208
5209
5210
5211
5212
5213
5214
5215
5216
5217
5218
5219
5220
5221
5222
5223
5224
5225
5226
5227
5228
5229
5230
5231
5232
5233
5234
5235
5236
5237
5238
5239
5240
5241
5242
5243
5244
5245
5246
5247
5248
5249
5250
5251
5252
5253
5254
5255
5256
5257
5258
5259
5260
5261
5262
5263
5264
5265
5266
5267
5268
5269
5270
5271
5272
5273
5274
5275
5276
5277
5278
5279
5280
5281
5282
5283
5284
5285
5286
5287
5288
5289
5290
5291
5292
5293
5294
5295
5296
5297
5298
5299
5300
5301
5302
5303
5304
5305
5306
5307
5308
5309
5310
5311
5312
5313
5314
5315
5316
5317
5318
5319
5320
5321
5322
5323
5324
5325
5326
5327
5328
5329
5330
5331
5332
5333
5334
5335
5336
5337
5338
5339
5340
5341
5342
5343
5344
5345
5346
5347
5348
5349
5350
5351
5352
5353
5354
5355
5356
5357
5358
5359
5360
5361
5362
5363
5364
5365
5366
5367
5368
5369
5370
5371
5372
5373
5374
5375
5376
5377
5378
5379
5380
5381
5382
5383
5384
5385
5386
5387
5388
5389
5390
5391
5392
5393
5394
5395
5396
5397
5398
5399
5400
5401
5402
5403
5404
5405
5406
5407
5408
5409
5410
5411
5412
5413
5414
5415
5416
5417
5418
5419
5420
5421
5422
5423
5424
5425
5426
5427
5428
5429
5430
5431
5432
5433
5434
5435
5436
5437
5438
5439
5440
5441
5442
5443
5444
5445
5446
5447
5448
5449
5450
5451
5452
5453
5454
5455
5456
5457
5458
5459
5460
5461
5462
5463
5464
5465
5466
5467
5468
5469
5470
5471
5472
5473
5474
5475
5476
5477
5478
5479
5480
5481
5482
5483
5484
5485
5486
5487
5488
5489
5490
5491
5492
5493
5494
5495
5496
5497
5498
5499
5500
5501
5502
5503
5504
5505
5506
5507
5508
5509
5510
5511
5512
5513
5514
5515
5516
5517
5518
5519
5520
5521
5522
5523
5524
5525
5526
5527
5528
5529
5530
5531
5532
5533
5534
5535
5536
5537
5538
5539
5540
5541
5542
5543
5544
5545
5546
5547
5548
5549
5550
5551
5552
5553
5554
5555
5556
5557
5558
5559
5560
5561
5562
5563
5564
5565
5566
5567
5568
5569
5570
5571
5572
5573
5574
5575
5576
5577
5578
5579
5580
5581
5582
5583
5584
5585
5586
5587
5588
5589
5590
5591
5592
5593
5594
5595
5596
5597
5598
5599
5600
5601
5602
5603
5604
5605
5606
5607
5608
5609
5610
5611
5612
5613
5614
5615
5616
5617
5618
5619
5620
5621
5622
5623
5624
5625
5626
5627
5628
5629
5630
5631
5632
5633
5634
5635
5636
5637
5638
5639
5640
5641
5642
5643
5644
5645
5646
5647
5648
5649
5650
5651
5652
5653
5654
5655
5656
5657
5658
5659
5660
5661
5662
5663
5664
5665
5666
5667
5668
5669
5670
5671
5672
5673
5674
5675
5676
5677
5678
5679
5680
5681
5682
5683
5684
5685
5686
5687
5688
5689
5690
5691
5692
5693
5694
5695
5696
5697
5698
5699
5700
5701
5702
5703
5704
5705
5706
5707
5708
5709
5710
5711
5712
5713
5714
5715
5716
5717
5718
5719
5720
5721
5722
5723
5724
5725
5726
5727
5728
5729
5730
5731
5732
5733
5734
5735
5736
5737
5738
5739
5740
5741
5742
5743
5744
5745
5746
5747
5748
5749
5750
5751
5752
5753
5754
5755
5756
5757
5758
5759
5760
5761
5762
5763
5764
5765
5766
5767
5768
5769
5770
5771
5772
5773
5774
5775
5776
5777
5778
5779
5780
5781
5782
5783
5784
5785
5786
5787
5788
5789
5790
5791
5792
5793
5794
5795
5796
5797
5798
5799
5800
5801
5802
5803
5804
5805
5806
5807
5808
5809
5810
5811
5812
5813
5814
5815
5816
5817
5818
5819
5820
5821
5822
5823
5824
5825
5826
5827
5828
5829
5830
5831
5832
5833
5834
5835
5836
5837
5838
5839
5840
5841
5842
5843
5844
5845
5846
5847
5848
5849
5850
5851
5852
5853
5854
5855
5856
5857
5858
5859
5860
5861
5862
5863
5864
5865
5866
5867
5868
5869
5870
5871
5872
5873
5874
5875
5876
5877
5878
5879
5880
5881
5882
5883
5884
5885
5886
5887
5888
5889
5890
5891
5892
5893
5894
5895
5896
5897
5898
5899
5900
5901
5902
5903
5904
5905
5906
5907
5908
5909
5910
5911
5912
5913
5914
5915
5916
5917
5918
5919
5920
5921
5922
5923
5924
5925
5926
5927
5928
5929
5930
5931
5932
5933
5934
5935
5936
5937
5938
5939
5940
5941
5942
5943
5944
5945
5946
5947
5948
5949
5950
5951
5952
5953
5954
5955
5956
5957
5958
5959
5960
5961
5962
5963
5964
5965
5966
5967
5968
5969
5970
5971
5972
5973
5974
5975
5976
5977
5978
5979
5980
5981
5982
5983
5984
5985
5986
5987
5988
5989
5990
5991
5992
5993
5994
5995
5996
5997
5998
5999
6000
6001
6002
6003
6004
6005
6006
6007
6008
6009
6010
6011
6012
6013
6014
6015
6016
6017
6018
6019
6020
6021
6022
6023
6024
6025
6026
6027
6028
6029
6030
6031
6032
6033
6034
6035
6036
6037
6038
6039
6040
6041
6042
6043
6044
6045
6046
6047
6048
6049
6050
6051
6052
6053
6054
6055
6056
6057
6058
6059
6060
6061
6062
6063
6064
6065
6066
6067
6068
6069
6070
6071
6072
6073
6074
6075
6076
6077
6078
6079
6080
6081
6082
6083
6084
6085
6086
6087
6088
6089
6090
6091
6092
6093
6094
6095
6096
6097
6098
6099
6100
6101
6102
6103
6104
6105
6106
6107
6108
6109
6110
6111
6112
6113
6114
6115
6116
6117
6118
6119
6120
6121
6122
6123
6124
6125
6126
6127
6128
6129
6130
6131
6132
6133
6134
6135
6136
6137
6138
6139
6140
6141
6142
6143
6144
6145
6146
6147
6148
6149
6150
6151
6152
6153
6154
6155
6156
6157
6158
6159
6160
6161
6162
6163
6164
6165
6166
6167
6168
6169
6170
6171
6172
6173
6174
6175
6176
6177
6178
6179
6180
6181
6182
6183
6184
6185
6186
6187
6188
6189
6190
6191
6192
6193
6194
6195
6196
6197
6198
6199
6200
6201
6202
6203
6204
6205
6206
6207
6208
6209
6210
6211
6212
6213
6214
6215
6216
6217
6218
6219
6220
6221
6222
6223
6224
6225
6226
6227
6228
6229
6230
6231
6232
6233
6234
6235
6236
6237
6238
6239
6240
6241
6242
6243
6244
6245
6246
6247
6248
6249
6250
6251
6252
6253
6254
6255
6256
6257
6258
6259
6260
6261
6262
6263
6264
6265
6266
6267
6268
6269
6270
6271
6272
6273
6274
6275
6276
6277
6278
6279
6280
6281
6282
6283
6284
6285
6286
6287
6288
6289
6290
6291
6292
6293
6294
6295
6296
6297
6298
6299
6300
6301
6302
6303
6304
6305
6306
6307
6308
6309
6310
6311
6312
6313
6314
6315
6316
6317
6318
6319
6320
6321
6322
6323
6324
6325
6326
6327
6328
6329
6330
6331
6332
6333
6334
6335
6336
6337
6338
6339
6340
6341
6342
6343
6344
6345
6346
6347
6348
6349
6350
6351
6352
6353
6354
6355
6356
6357
6358
6359
6360
6361
6362
6363
6364
6365
6366
6367
6368
6369
6370
6371
6372
6373
6374
6375
6376
6377
6378
6379
6380
6381
6382
6383
6384
6385
6386
6387
6388
6389
6390
6391
6392
6393
6394
6395
6396
6397
6398
6399
6400
6401
6402
6403
6404
6405
6406
6407
6408
6409
6410
6411
6412
6413
6414
6415
6416
6417
6418
6419
6420
6421
6422
6423
6424
6425
6426
6427
6428
6429
6430
6431
6432
6433
6434
6435
6436
6437
6438
6439
6440
6441
6442
6443
6444
6445
6446
6447
6448
6449
6450
6451
6452
6453
6454
6455
6456
6457
6458
6459
6460
6461
6462
6463
6464
6465
6466
6467
6468
6469
6470
6471
6472
6473
6474
6475
6476
6477
6478
6479
6480
6481
6482
6483
6484
6485
6486
6487
6488
6489
6490
6491
6492
6493
6494
6495
6496
6497
6498
6499
6500
6501
6502
6503
6504
6505
6506
6507
6508
6509
6510
6511
6512
6513
6514
6515
6516
6517
6518
6519
6520
6521
6522
6523
6524
6525
6526
6527
6528
6529
6530
6531
6532
6533
6534
6535
6536
6537
6538
6539
6540
6541
6542
6543
6544
6545
6546
6547
6548
6549
6550
6551
6552
6553
6554
6555
6556
6557
6558
6559
6560
6561
6562
6563
6564
6565
6566
6567
6568
6569
6570
6571
6572
6573
6574
6575
6576
6577
6578
6579
6580
6581
6582
6583
6584
6585
6586
6587
6588
6589
6590
6591
6592
6593
6594
6595
6596
6597
6598
6599
6600
6601
6602
6603
6604
6605
6606
6607
6608
6609
6610
6611
6612
6613
6614
6615
6616
6617
6618
6619
6620
6621
6622
6623
6624
6625
6626
6627
6628
6629
6630
6631
6632
6633
6634
6635
6636
6637
6638
6639
6640
6641
6642
6643
6644
6645
6646
6647
6648
6649
6650
6651
6652
6653
6654
6655
6656
6657
6658
6659
6660
6661
6662
6663
6664
6665
6666
6667
6668
6669
6670
6671
6672
6673
6674
6675
6676
6677
6678
6679
6680
6681
6682
6683
6684
6685
6686
6687
6688
6689
6690
6691
6692
6693
6694
6695
6696
6697
6698
6699
6700
6701
6702
6703
6704
6705
6706
6707
6708
6709
6710
6711
6712
6713
6714
6715
6716
6717
6718
6719
6720
6721
6722
6723
6724
6725
6726
6727
6728
6729
6730
6731
6732
6733
6734
6735
6736
6737
6738
6739
6740
6741
6742
6743
6744
6745
6746
6747
6748
6749
6750
6751
6752
6753
6754
6755
6756
6757
6758
6759
6760
6761
6762
6763
6764
6765
6766
6767
6768
6769
6770
6771
6772
6773
6774
6775
6776
6777
6778
6779
6780
6781
6782
6783
6784
6785
6786
6787
6788
6789
6790
6791
6792
6793
6794
6795
6796
6797
6798
6799
6800
6801
6802
6803
6804
6805
6806
6807
6808
6809
6810
6811
6812
6813
6814
6815
6816
6817
6818
6819
6820
6821
6822
6823
6824
6825
6826
6827
6828
6829
6830
6831
6832
6833
6834
6835
6836
6837
6838
6839
6840
6841
6842
6843
6844
6845
6846
6847
6848
6849
6850
6851
6852
6853
6854
6855
6856
6857
6858
6859
6860
6861
6862
6863
6864
6865
6866
6867
6868
6869
6870
6871
6872
6873
6874
6875
6876
6877
6878
6879
6880
6881
6882
6883
6884
6885
6886
6887
6888
6889
6890
6891
6892
6893
6894
6895
6896
6897
6898
6899
6900
6901
6902
6903
6904
6905
6906
6907
6908
6909
6910
6911
6912
6913
6914
6915
6916
6917
6918
6919
6920
6921
6922
6923
6924
6925
6926
6927
6928
6929
6930
6931
6932
6933
6934
6935
6936
6937
6938
6939
6940
6941
6942
6943
6944
6945
6946
6947
6948
6949
6950
6951
6952
6953
6954
6955
6956
6957
6958
6959
6960
6961
6962
6963
6964
6965
6966
6967
6968
6969
6970
6971
6972
6973
6974
6975
6976
6977
6978
6979
6980
6981
6982
6983
6984
6985
6986
6987
6988
6989
6990
6991
6992
6993
6994
6995
6996
6997
6998
6999
7000
7001
7002
7003
7004
7005
7006
7007
7008
7009
7010
7011
7012
7013
7014
7015
7016
7017
7018
7019
7020
7021
7022
7023
7024
7025
7026
7027
7028
7029
7030
7031
7032
7033
7034
7035
7036
7037
7038
7039
7040
7041
7042
7043
7044
7045
7046
7047
7048
7049
7050
7051
7052
7053
7054
7055
7056
7057
7058
7059
7060
7061
7062
7063
7064
7065
7066
7067
7068
7069
7070
7071
7072
7073
7074
7075
7076
7077
7078
7079
7080
7081
7082
7083
7084
7085
7086
7087
7088
7089
7090
7091
7092
7093
7094
7095
7096
7097
7098
7099
7100
7101
7102
7103
7104
7105
7106
7107
7108
7109
7110
7111
7112
7113
7114
7115
7116
7117
7118
7119
7120
7121
7122
7123
7124
7125
7126
7127
7128
7129
7130
7131
7132
7133
7134
7135
7136
7137
7138
7139
7140
7141
7142
7143
7144
7145
7146
7147
7148
7149
7150
7151
7152
7153
7154
7155
7156
7157
7158
7159
7160
7161
7162
7163
7164
7165
7166
7167
7168
7169
7170
7171
7172
7173
7174
7175
7176
7177
7178
7179
7180
7181
7182
7183
7184
7185
7186
7187
7188
7189
7190
7191
7192
7193
7194
7195
7196
7197
7198
7199
7200
7201
7202
7203
7204
7205
7206
7207
7208
7209
7210
7211
7212
7213
7214
7215
7216
7217
7218
7219
7220
7221
7222
7223
7224
7225
7226
7227
7228
7229
7230
7231
7232
7233
7234
7235
7236
7237
7238
7239
7240
7241
7242
7243
7244
7245
7246
7247
7248
7249
7250
7251
7252
7253
7254
7255
7256
7257
7258
7259
7260
7261
7262
7263
7264
7265
7266
7267
7268
7269
7270
7271
7272
7273
7274
7275
7276
7277
7278
7279
7280
7281
7282
7283
7284
7285
7286
7287
7288
7289
7290
7291
7292
7293
7294
7295
7296
7297
7298
7299
7300
7301
7302
7303
7304
7305
7306
7307
7308
7309
7310
7311
7312
7313
7314
7315
7316
7317
7318
7319
7320
7321
7322
7323
7324
7325
7326
7327
7328
7329
7330
7331
7332
7333
7334
7335
7336
7337
7338
7339
7340
7341
7342
7343
7344
7345
7346
7347
7348
7349
7350
7351
7352
7353
7354
7355
7356
7357
7358
7359
7360
7361
7362
7363
7364
7365
7366
7367
7368
7369
7370
7371
7372
7373
7374
7375
7376
7377
7378
7379
7380
7381
7382
7383
7384
7385
7386
7387
7388
7389
7390
7391
7392
7393
7394
7395
7396
7397
7398
7399
7400
7401
7402
7403
7404
7405
7406
7407
7408
7409
7410
7411
7412
7413
7414
7415
7416
7417
7418
7419
7420
7421
7422
7423
7424
7425
7426
7427
7428
7429
7430
7431
7432
7433
7434
7435
7436
7437
7438
7439
7440
7441
7442
7443
7444
7445
7446
7447
7448
7449
7450
7451
7452
7453
7454
7455
7456
7457
7458
7459
7460
7461
7462
7463
7464
7465
7466
7467
7468
7469
7470
7471
7472
7473
7474
7475
7476
7477
7478
7479
7480
7481
7482
7483
7484
7485
7486
7487
7488
7489
7490
7491
7492
7493
7494
7495
7496
7497
7498
7499
7500
7501
7502
7503
7504
7505
7506
7507
7508
7509
7510
7511
7512
7513
7514
7515
7516
7517
7518
7519
7520
7521
7522
7523
7524
7525
7526
7527
7528
7529
7530
7531
7532
7533
7534
7535
7536
7537
7538
7539
7540
7541
7542
7543
7544
7545
7546
7547
7548
7549
7550
7551
7552
7553
7554
7555
7556
7557
7558
7559
7560
7561
7562
7563
7564
7565
7566
7567
7568
7569
7570
7571
7572
7573
7574
7575
7576
7577
7578
7579
7580
7581
7582
7583
7584
7585
7586
7587
7588
7589
7590
7591
7592
7593
7594
7595
7596
7597
7598
7599
7600
7601
7602
7603
7604
7605
7606
7607
7608
7609
7610
7611
7612
7613
7614
7615
7616
7617
7618
7619
7620
7621
7622
7623
7624
7625
7626
7627
7628
7629
7630
7631
7632
7633
7634
7635
7636
7637
7638
7639
7640
7641
7642
7643
7644
7645
7646
7647
7648
7649
7650
7651
7652
7653
7654
7655
7656
7657
7658
7659
7660
7661
7662
7663
7664
7665
7666
7667
7668
7669
7670
7671
7672
7673
7674
7675
7676
7677
7678
7679
7680
7681
7682
7683
7684
7685
7686
7687
7688
7689
7690
7691
7692
7693
7694
7695
7696
7697
7698
7699
7700
7701
7702
7703
7704
7705
7706
7707
7708
7709
7710
7711
7712
7713
7714
7715
7716
7717
7718
7719
7720
7721
7722
7723
7724
7725
7726
7727
7728
7729
7730
7731
7732
7733
7734
7735
7736
7737
7738
7739
7740
7741
7742
7743
7744
7745
7746
7747
7748
7749
7750
7751
7752
7753
7754
7755
7756
7757
7758
7759
7760
7761
7762
7763
7764
7765
7766
7767
7768
7769
7770
7771
7772
7773
7774
7775
7776
7777
7778
7779
7780
7781
7782
7783
7784
7785
7786
7787
7788
7789
7790
7791
7792
7793
7794
7795
7796
7797
7798
7799
7800
7801
7802
7803
7804
7805
7806
7807
7808
7809
7810
7811
7812
7813
7814
7815
7816
7817
7818
7819
7820
7821
7822
7823
7824
7825
7826
7827
7828
7829
7830
7831
7832
7833
7834
7835
7836
7837
7838
7839
7840
7841
7842
7843
7844
7845
7846
7847
7848
7849
7850
7851
7852
7853
7854
7855
7856
7857
7858
7859
7860
7861
7862
7863
7864
7865
7866
7867
7868
7869
7870
7871
7872
7873
7874
7875
7876
7877
7878
7879
7880
7881
7882
7883
7884
7885
7886
7887
7888
7889
7890
7891
7892
7893
7894
7895
7896
7897
7898
7899
7900
7901
7902
7903
7904
7905
7906
7907
7908
7909
7910
7911
7912
7913
7914
7915
7916
7917
7918
7919
7920
7921
7922
7923
7924
7925
7926
7927
7928
7929
7930
7931
7932
7933
7934
7935
7936
7937
7938
7939
7940
7941
7942
7943
7944
7945
7946
7947
7948
7949
7950
7951
7952
7953
7954
7955
7956
7957
7958
7959
7960
7961
7962
7963
7964
7965
7966
7967
7968
7969
7970
7971
7972
7973
7974
7975
7976
7977
7978
7979
7980
7981
7982
7983
7984
7985
7986
7987
7988
7989
7990
7991
7992
7993
7994
7995
7996
7997
7998
7999
8000
8001
8002
8003
8004
8005
8006
8007
8008
8009
8010
8011
8012
8013
8014
8015
8016
8017
8018
8019
8020
8021
8022
8023
8024
8025
8026
8027
8028
8029
8030
8031
8032
8033
8034
8035
8036
8037
8038
8039
8040
8041
8042
8043
8044
8045
8046
8047
8048
8049
8050
8051
8052
8053
8054
8055
8056
8057
8058
8059
8060
8061
8062
8063
8064
8065
8066
8067
8068
8069
8070
8071
8072
8073
8074
8075
8076
8077
8078
8079
8080
8081
8082
8083
8084
8085
8086
8087
8088
8089
8090
8091
8092
8093
8094
8095
8096
8097
8098
8099
8100
8101
8102
8103
8104
8105
8106
8107
8108
8109
8110
8111
8112
8113
8114
8115
8116
8117
8118
8119
8120
8121
8122
8123
8124
8125
8126
8127
8128
8129
8130
8131
8132
8133
8134
8135
8136
8137
8138
8139
8140
8141
8142
8143
8144
8145
8146
8147
8148
8149
8150
8151
8152
8153
8154
8155
8156
8157
8158
8159
8160
8161
8162
8163
8164
8165
8166
8167
8168
8169
8170
8171
8172
8173
8174
8175
8176
8177
8178
8179
8180
8181
8182
8183
8184
8185
8186
8187
8188
8189
8190
8191
8192
8193
8194
8195
8196
8197
8198
8199
8200
8201
8202
8203
8204
8205
8206
8207
8208
8209
8210
8211
8212
8213
8214
8215
8216
8217
8218
8219
8220
8221
8222
8223
8224
8225
8226
8227
8228
8229
8230
8231
8232
8233
8234
8235
8236
8237
8238
8239
8240
8241
8242
8243
8244
8245
8246
8247
8248
8249
8250
8251
8252
8253
8254
8255
8256
8257
8258
8259
8260
8261
8262
8263
8264
8265
8266
8267
8268
8269
8270
8271
8272
8273
8274
8275
8276
8277
8278
8279
8280
8281
8282
8283
8284
8285
8286
8287
8288
8289
8290
8291
8292
8293
8294
8295
8296
8297
8298
8299
8300
8301
8302
8303
8304
8305
8306
8307
8308
8309
8310
8311
8312
8313
8314
8315
8316
8317
8318
8319
8320
8321
8322
8323
8324
8325
8326
8327
8328
8329
8330
8331
8332
8333
8334
8335
8336
8337
8338
8339
8340
8341
8342
8343
8344
8345
8346
8347
8348
8349
8350
8351
8352
8353
8354
8355
8356
8357
8358
8359
8360
8361
8362
8363
8364
8365
8366
8367
8368
8369
8370
8371
8372
8373
8374
8375
8376
8377
8378
8379
8380
8381
8382
8383
8384
8385
8386
8387
8388
8389
8390
8391
8392
8393
8394
8395
8396
8397
8398
8399
8400
8401
8402
8403
8404
8405
8406
8407
8408
8409
8410
8411
8412
8413
8414
8415
8416
8417
8418
8419
8420
8421
8422
8423
8424
8425
8426
8427
8428
8429
8430
8431
8432
8433
8434
8435
8436
8437
8438
8439
8440
8441
8442
8443
8444
8445
8446
8447
8448
8449
8450
8451
8452
8453
8454
8455
8456
8457
8458
8459
8460
8461
8462
8463
8464
8465
8466
8467
8468
8469
8470
8471
8472
8473
8474
8475
8476
8477
8478
8479
8480
8481
8482
8483
8484
8485
8486
8487
8488
8489
8490
8491
8492
8493
8494
8495
8496
8497
8498
8499
8500
8501
8502
8503
8504
8505
8506
8507
8508
8509
8510
8511
8512
8513
8514
8515
8516
8517
8518
8519
8520
8521
8522
8523
8524
8525
8526
8527
8528
8529
8530
8531
8532
8533
8534
8535
8536
8537
8538
8539
8540
8541
8542
8543
8544
8545
8546
8547
8548
8549
8550
8551
8552
8553
8554
8555
8556
8557
8558
8559
8560
8561
8562
8563
8564
8565
8566
8567
8568
8569
8570
8571
8572
8573
8574
8575
8576
8577
8578
8579
8580
8581
8582
8583
8584
8585
8586
8587
8588
8589
8590
8591
8592
8593
8594
8595
8596
8597
8598
8599
8600
8601
8602
8603
8604
8605
8606
8607
8608
8609
8610
8611
8612
8613
8614
8615
8616
8617
8618
8619
8620
8621
8622
8623
8624
8625
8626
8627
8628
8629
8630
8631
8632
8633
8634
8635
8636
8637
8638
8639
8640
8641
8642
8643
8644
8645
8646
8647
8648
8649
8650
8651
8652
8653
8654
8655
8656
8657
8658
8659
8660
8661
8662
8663
8664
8665
8666
8667
8668
8669
8670
8671
8672
8673
8674
8675
8676
8677
8678
8679
8680
8681
8682
8683
8684
8685
8686
8687
8688
8689
8690
8691
8692
8693
8694
8695
8696
8697
8698
8699
8700
8701
8702
8703
8704
8705
8706
8707
8708
8709
8710
8711
8712
8713
8714
8715
8716
8717
8718
8719
8720
8721
8722
8723
8724
8725
8726
8727
8728
8729
8730
8731
8732
8733
8734
8735
8736
8737
8738
8739
8740
8741
8742
8743
8744
8745
8746
8747
8748
8749
8750
8751
8752
8753
8754
8755
8756
8757
8758
8759
8760
8761
8762
8763
8764
8765
8766
8767
8768
8769
8770
8771
8772
8773
8774
8775
8776
8777
8778
8779
8780
8781
8782
8783
8784
8785
8786
8787
8788
8789
8790
8791
8792
8793
8794
8795
8796
8797
8798
8799
8800
8801
8802
8803
8804
8805
8806
8807
8808
8809
8810
8811
8812
8813
8814
8815
8816
8817
8818
8819
8820
8821
8822
8823
8824
8825
8826
8827
8828
8829
8830
8831
8832
8833
8834
8835
8836
8837
8838
8839
8840
8841
8842
8843
8844
8845
8846
8847
8848
8849
8850
8851
8852
8853
8854
8855
8856
8857
8858
8859
8860
8861
8862
8863
8864
8865
8866
8867
8868
8869
8870
8871
8872
8873
8874
8875
8876
8877
8878
8879
8880
8881
8882
8883
8884
8885
8886
8887
8888
8889
8890
8891
8892
8893
8894
8895
8896
8897
8898
8899
8900
8901
8902
8903
8904
8905
8906
8907
8908
8909
8910
8911
8912
8913
8914
8915
8916
8917
8918
8919
8920
8921
8922
8923
8924
8925
8926
8927
8928
8929
8930
8931
8932
8933
8934
8935
8936
8937
8938
8939
8940
8941
8942
8943
8944
8945
8946
8947
8948
8949
8950
8951
8952
8953
8954
8955
8956
8957
8958
8959
8960
8961
8962
8963
8964
8965
8966
8967
8968
8969
8970
8971
8972
8973
8974
8975
8976
8977
8978
8979
8980
8981
8982
8983
8984
8985
8986
8987
8988
8989
8990
8991
8992
8993
8994
8995
8996
8997
8998
8999
9000
9001
9002
9003
9004
9005
9006
9007
9008
9009
9010
9011
9012
9013
9014
9015
9016
9017
9018
9019
9020
9021
9022
9023
9024
9025
9026
9027
9028
9029
9030
9031
9032
9033
9034
9035
9036
9037
9038
9039
9040
9041
9042
9043
9044
9045
9046
9047
9048
9049
9050
9051
9052
9053
9054
9055
9056
9057
9058
9059
9060
9061
9062
9063
9064
9065
9066
9067
9068
9069
9070
9071
9072
9073
9074
9075
9076
9077
9078
9079
9080
9081
9082
9083
9084
9085
9086
9087
9088
9089
9090
9091
9092
9093
9094
9095
9096
9097
9098
9099
9100
9101
9102
9103
9104
9105
9106
9107
9108
9109
9110
9111
9112
9113
9114
9115
9116
9117
9118
9119
9120
9121
9122
9123
9124
9125
9126
9127
9128
9129
9130
9131
9132
9133
9134
9135
9136
9137
9138
9139
9140
9141
9142
9143
9144
9145
9146
9147
9148
9149
9150
9151
9152
9153
9154
9155
9156
9157
9158
9159
9160
9161
9162
9163
9164
9165
9166
9167
9168
9169
9170
9171
9172
9173
9174
9175
9176
9177
9178
9179
9180
9181
9182
9183
9184
9185
9186
9187
9188
9189
9190
9191
9192
9193
9194
9195
9196
9197
9198
9199
9200
9201
9202
9203
9204
9205
9206
9207
9208
9209
9210
9211
9212
9213
9214
9215
9216
9217
9218
9219
9220
9221
9222
9223
9224
9225
9226
9227
9228
9229
9230
9231
9232
9233
9234
9235
9236
9237
9238
9239
9240
9241
9242
9243
9244
9245
9246
9247
9248
9249
9250
9251
9252
9253
9254
9255
9256
9257
9258
9259
9260
9261
9262
9263
9264
9265
9266
9267
9268
9269
9270
9271
9272
9273
9274
9275
9276
9277
9278
9279
9280
9281
9282
9283
9284
9285
9286
9287
9288
9289
9290
9291
9292
9293
9294
9295
9296
9297
9298
9299
9300
9301
9302
9303
9304
9305
9306
9307
9308
9309
9310
9311
9312
9313
9314
9315
9316
9317
9318
9319
9320
9321
9322
9323
9324
9325
9326
9327
9328
9329
9330
9331
9332
9333
9334
9335
9336
9337
9338
9339
9340
9341
9342
9343
9344
9345
9346
9347
9348
9349
9350
9351
9352
9353
9354
9355
9356
9357
9358
9359
9360
9361
9362
9363
9364
9365
9366
9367
9368
9369
9370
9371
9372
9373
9374
9375
9376
9377
9378
9379
9380
9381
9382
9383
9384
9385
9386
9387
9388
9389
9390
9391
9392
9393
9394
9395
9396
9397
9398
9399
9400
9401
9402
9403
9404
9405
9406
9407
9408
9409
9410
9411
9412
9413
9414
9415
9416
9417
9418
9419
9420
9421
9422
9423
9424
9425
9426
9427
9428
9429
9430
9431
9432
9433
9434
9435
9436
9437
9438
9439
9440
9441
9442
9443
9444
9445
9446
9447
9448
9449
9450
9451
9452
9453
9454
9455
9456
9457
9458
9459
9460
9461
9462
9463
9464
9465
9466
9467
9468
9469
9470
9471
9472
9473
9474
9475
9476
9477
9478
9479
9480
9481
9482
9483
9484
9485
9486
9487
9488
9489
9490
9491
9492
9493
9494
9495
9496
9497
9498
9499
9500
9501
9502
9503
9504
9505
9506
9507
9508
9509
9510
9511
9512
9513
9514
9515
9516
9517
9518
9519
9520
9521
9522
9523
9524
9525
9526
9527
9528
9529
9530
9531
9532
9533
9534
9535
9536
9537
9538
9539
9540
9541
9542
9543
9544
9545
9546
9547
9548
9549
9550
9551
9552
9553
9554
9555
9556
9557
9558
9559
9560
9561
9562
9563
9564
9565
9566
9567
9568
9569
9570
9571
9572
9573
9574
9575
9576
9577
9578
9579
9580
9581
9582
9583
9584
9585
9586
9587
9588
9589
9590
9591
9592
9593
9594
9595
9596
9597
9598
9599
9600
9601
9602
9603
9604
9605
9606
9607
9608
9609
9610
9611
9612
9613
9614
9615
9616
9617
9618
9619
9620
9621
9622
9623
9624
9625
9626
9627
9628
9629
9630
9631
9632
9633
9634
9635
9636
9637
9638
9639
9640
9641
9642
9643
9644
9645
9646
9647
9648
9649
9650
9651
9652
9653
9654
9655
9656
9657
9658
9659
9660
9661
9662
9663
9664
9665
9666
9667
9668
9669
9670
9671
9672
9673
9674
9675
9676
9677
9678
9679
9680
9681
9682
9683
9684
9685
9686
9687
9688
9689
9690
9691
9692
9693
9694
9695
9696
9697
9698
9699
9700
9701
9702
9703
9704
9705
9706
9707
9708
9709
9710
9711
9712
9713
9714
9715
9716
9717
9718
9719
9720
9721
9722
9723
9724
9725
9726
9727
9728
9729
9730
9731
9732
9733
9734
9735
9736
9737
9738
9739
9740
9741
9742
9743
9744
9745
9746
9747
9748
9749
9750
9751
9752
9753
9754
9755
9756
9757
9758
9759
9760
9761
9762
9763
9764
9765
9766
9767
9768
9769
9770
9771
9772
9773
9774
9775
9776
9777
9778
9779
9780
9781
9782
9783
9784
9785
9786
9787
9788
9789
9790
9791
9792
9793
9794
9795
9796
9797
9798
9799
9800
9801
9802
9803
9804
9805
9806
9807
9808
9809
9810
9811
9812
9813
9814
9815
9816
9817
9818
9819
9820
9821
9822
9823
9824
9825
9826
9827
9828
9829
9830
9831
9832
9833
9834
9835
9836
9837
9838
9839
9840
9841
9842
9843
9844
9845
9846
9847
9848
9849
9850
9851
9852
9853
9854
9855
9856
9857
9858
9859
9860
9861
9862
9863
9864
9865
9866
9867
9868
9869
9870
9871
9872
9873
9874
9875
9876
9877
9878
9879
9880
9881
9882
9883
9884
9885
9886
9887
9888
9889
9890
9891
9892
9893
9894
9895
9896
9897
9898
9899
9900
9901
9902
9903
9904
9905
9906
9907
9908
9909
9910
9911
9912
9913
9914
9915
9916
9917
9918
9919
9920
9921
9922
9923
9924
9925
9926
9927
9928
9929
9930
9931
9932
9933
9934
9935
9936
9937
9938
9939
9940
9941
9942
9943
9944
9945
9946
9947
9948
9949
9950
9951
9952
9953
9954
9955
9956
9957
9958
9959
9960
9961
9962
9963
9964
9965
9966
9967
9968
9969
9970
9971
9972
9973
9974
9975
9976
9977
9978
9979
9980
9981
9982
9983
9984
9985
9986
9987
9988
9989
9990
9991
9992
9993
9994
9995
9996
9997
9998
9999
10000
10001
10002
10003
10004
10005
10006
10007
10008
10009
10010
10011
10012
10013
10014
10015
10016
10017
10018
10019
10020
10021
10022
10023
10024
10025
10026
10027
10028
10029
10030
10031
10032
10033
10034
10035
10036
10037
10038
10039
10040
10041
10042
10043
10044
10045
10046
10047
10048
10049
10050
10051
10052
10053
10054
10055
10056
10057
10058
10059
10060
10061
10062
10063
10064
10065
10066
10067
10068
10069
10070
10071
10072
10073
10074
10075
10076
10077
10078
10079
10080
10081
10082
10083
10084
10085
10086
10087
10088
10089
10090
10091
10092
10093
10094
10095
10096
10097
10098
10099
10100
10101
10102
10103
10104
10105
10106
10107
10108
10109
10110
10111
10112
10113
10114
10115
10116
10117
10118
10119
10120
10121
10122
10123
10124
10125
10126
10127
10128
10129
10130
10131
10132
10133
10134
10135
10136
10137
10138
10139
10140
10141
10142
10143
10144
10145
10146
10147
10148
10149
10150
10151
10152
10153
10154
10155
10156
10157
10158
10159
10160
10161
10162
10163
10164
10165
10166
10167
10168
10169
10170
10171
10172
10173
10174
10175
10176
10177
10178
10179
10180
10181
10182
10183
10184
10185
10186
10187
10188
10189
10190
10191
10192
10193
10194
10195
10196
10197
10198
10199
10200
10201
10202
10203
10204
10205
10206
10207
10208
10209
10210
10211
10212
10213
10214
10215
10216
10217
10218
10219
10220
10221
10222
10223
10224
10225
10226
10227
10228
10229
10230
10231
10232
10233
10234
10235
10236
10237
10238
10239
10240
10241
10242
10243
10244
10245
10246
10247
10248
10249
10250
10251
10252
10253
10254
10255
10256
10257
10258
10259
10260
10261
10262
10263
10264
10265
10266
10267
10268
10269
10270
10271
10272
10273
10274
10275
10276
10277
10278
10279
10280
10281
10282
10283
10284
10285
10286
10287
10288
10289
10290
10291
10292
10293
10294
10295
10296
10297
10298
10299
10300
10301
10302
10303
10304
10305
10306
10307
10308
10309
10310
10311
10312
10313
10314
10315
10316
10317
10318
10319
10320
10321
10322
10323
10324
10325
10326
10327
10328
10329
10330
10331
10332
10333
10334
10335
10336
10337
10338
10339
10340
10341
10342
10343
10344
10345
10346
10347
10348
10349
10350
10351
10352
10353
10354
10355
10356
10357
10358
10359
10360
10361
10362
10363
10364
10365
10366
10367
10368
10369
10370
10371
10372
10373
10374
10375
10376
10377
10378
10379
10380
10381
10382
10383
10384
10385
10386
10387
10388
10389
10390
10391
10392
10393
10394
10395
10396
10397
10398
10399
10400
10401
10402
10403
10404
10405
10406
10407
10408
10409
10410
10411
10412
10413
10414
10415
10416
10417
10418
10419
10420
10421
10422
10423
10424
10425
10426
10427
10428
10429
10430
10431
10432
10433
10434
10435
10436
10437
10438
10439
10440
10441
10442
10443
10444
10445
10446
10447
10448
10449
10450
10451
10452
10453
10454
10455
10456
10457
10458
10459
10460
10461
10462
10463
10464
10465
10466
10467
10468
10469
10470
10471
10472
10473
10474
10475
10476
10477
10478
10479
10480
10481
10482
10483
10484
10485
10486
10487
10488
10489
10490
10491
10492
10493
10494
10495
10496
10497
10498
10499
10500
10501
10502
10503
10504
10505
10506
10507
10508
10509
10510
10511
10512
10513
10514
10515
10516
10517
10518
10519
10520
10521
10522
10523
10524
10525
10526
10527
10528
10529
10530
10531
10532
10533
10534
10535
10536
10537
10538
10539
10540
10541
10542
10543
10544
10545
10546
10547
10548
10549
10550
10551
10552
10553
10554
10555
10556
10557
10558
10559
10560
10561
10562
10563
10564
10565
10566
10567
10568
10569
10570
10571
10572
10573
10574
10575
10576
10577
10578
10579
10580
10581
10582
10583
10584
10585
10586
10587
10588
10589
10590
10591
10592
10593
10594
10595
10596
10597
10598
10599
10600
10601
10602
10603
10604
10605
10606
10607
10608
10609
10610
10611
10612
10613
10614
10615
10616
10617
10618
10619
10620
10621
10622
10623
10624
10625
10626
10627
10628
10629
10630
10631
10632
10633
10634
10635
10636
10637
10638
10639
10640
10641
10642
10643
10644
10645
10646
10647
10648
10649
10650
10651
10652
10653
10654
10655
10656
10657
10658
10659
10660
10661
10662
10663
10664
10665
10666
10667
10668
10669
10670
10671
10672
10673
10674
10675
10676
10677
10678
10679
10680
10681
10682
10683
10684
10685
10686
10687
10688
10689
10690
10691
10692
10693
10694
10695
10696
10697
10698
10699
10700
10701
10702
10703
10704
10705
10706
10707
10708
10709
10710
10711
10712
10713
10714
10715
10716
10717
10718
10719
10720
10721
10722
10723
10724
10725
10726
10727
10728
10729
10730
10731
10732
10733
10734
10735
10736
10737
10738
10739
10740
10741
10742
10743
10744
10745
10746
10747
10748
10749
10750
10751
10752
10753
10754
10755
10756
10757
10758
10759
10760
10761
10762
10763
10764
10765
10766
10767
10768
10769
10770
10771
10772
10773
10774
10775
10776
10777
10778
10779
10780
10781
10782
10783
10784
10785
10786
10787
10788
10789
10790
10791
10792
10793
10794
10795
10796
10797
10798
10799
10800
10801
10802
10803
10804
10805
10806
10807
10808
10809
10810
10811
10812
10813
10814
10815
10816
10817
10818
10819
10820
10821
10822
10823
10824
10825
10826
10827
10828
10829
10830
10831
10832
10833
10834
10835
10836
10837
10838
10839
10840
10841
10842
10843
10844
10845
10846
10847
10848
10849
10850
10851
10852
10853
10854
10855
10856
10857
10858
10859
10860
10861
10862
10863
10864
10865
10866
10867
10868
10869
10870
10871
10872
10873
10874
10875
10876
10877
10878
10879
10880
10881
10882
10883
10884
10885
10886
10887
10888
10889
10890
10891
10892
10893
10894
10895
10896
10897
10898
10899
10900
10901
10902
10903
10904
10905
10906
10907
10908
10909
10910
10911
10912
10913
10914
10915
10916
10917
10918
10919
10920
10921
10922
10923
10924
10925
10926
10927
10928
10929
10930
10931
10932
10933
10934
10935
10936
10937
10938
10939
10940
10941
10942
10943
10944
10945
10946
10947
10948
10949
10950
10951
10952
10953
10954
10955
10956
10957
10958
10959
10960
10961
10962
10963
10964
10965
10966
10967
10968
10969
10970
10971
10972
10973
10974
10975
10976
10977
10978
10979
10980
10981
10982
10983
10984
10985
10986
10987
10988
10989
10990
10991
10992
10993
10994
10995
10996
10997
10998
10999
11000
11001
11002
11003
11004
11005
11006
11007
11008
11009
11010
11011
11012
11013
11014
11015
11016
11017
11018
11019
11020
11021
11022
11023
11024
11025
11026
11027
11028
11029
11030
11031
11032
11033
11034
11035
11036
11037
11038
11039
11040
11041
11042
11043
11044
11045
11046
11047
11048
11049
11050
11051
11052
11053
11054
11055
11056
11057
11058
11059
11060
11061
11062
11063
11064
11065
11066
11067
11068
11069
11070
11071
11072
11073
11074
11075
11076
11077
11078
11079
11080
11081
11082
11083
11084
11085
11086
11087
11088
11089
11090
11091
11092
11093
11094
11095
11096
11097
11098
11099
11100
11101
11102
11103
11104
11105
11106
11107
11108
11109
11110
11111
11112
11113
11114
11115
11116
11117
11118
11119
11120
11121
11122
11123
11124
11125
11126
11127
11128
11129
11130
11131
11132
11133
11134
11135
11136
11137
11138
11139
11140
11141
11142
11143
11144
11145
11146
11147
11148
11149
11150
11151
11152
11153
11154
11155
11156
11157
11158
11159
11160
11161
11162
11163
11164
11165
11166
11167
11168
11169
11170
11171
11172
11173
11174
11175
11176
11177
11178
11179
11180
11181
11182
11183
11184
11185
11186
11187
11188
11189
11190
11191
11192
11193
11194
11195
11196
11197
11198
11199
11200
11201
11202
11203
11204
11205
11206
11207
11208
11209
11210
11211
11212
11213
11214
11215
11216
11217
11218
11219
11220
11221
11222
11223
11224
11225
11226
11227
11228
11229
11230
11231
11232
11233
11234
11235
11236
11237
11238
11239
11240
11241
11242
11243
11244
11245
11246
11247
11248
11249
11250
11251
11252
11253
11254
11255
11256
11257
11258
11259
11260
11261
11262
11263
11264
11265
11266
11267
11268
11269
11270
11271
11272
11273
11274
11275
11276
11277
11278
11279
11280
11281
11282
11283
11284
11285
11286
11287
11288
11289
11290
11291
11292
11293
11294
11295
11296
11297
11298
11299
11300
11301
11302
11303
11304
11305
11306
11307
11308
11309
11310
11311
11312
11313
11314
11315
11316
11317
11318
11319
11320
11321
11322
11323
11324
11325
11326
11327
11328
11329
11330
11331
11332
11333
11334
11335
11336
11337
11338
11339
11340
11341
11342
11343
11344
11345
11346
11347
11348
11349
11350
11351
11352
11353
11354
11355
11356
11357
11358
11359
11360
11361
11362
11363
11364
11365
11366
11367
11368
11369
11370
11371
11372
11373
11374
11375
11376
11377
11378
11379
11380
11381
11382
11383
11384
11385
11386
11387
11388
11389
11390
11391
11392
11393
11394
11395
11396
11397
11398
11399
11400
11401
11402
11403
11404
11405
11406
11407
11408
11409
11410
11411
11412
11413
11414
11415
11416
11417
11418
11419
11420
11421
11422
11423
11424
11425
11426
11427
11428
11429
11430
11431
11432
11433
11434
11435
11436
11437
11438
11439
11440
11441
11442
11443
11444
11445
11446
11447
11448
11449
11450
11451
11452
11453
11454
11455
11456
11457
11458
11459
11460
11461
11462
11463
11464
11465
11466
11467
11468
11469
11470
11471
11472
11473
11474
11475
11476
11477
11478
11479
11480
11481
11482
11483
11484
11485
11486
11487
11488
11489
11490
11491
11492
11493
11494
11495
11496
11497
11498
11499
11500
11501
11502
11503
11504
11505
11506
11507
11508
11509
11510
11511
11512
11513
11514
11515
11516
11517
11518
11519
11520
11521
11522
11523
11524
11525
11526
11527
11528
11529
11530
11531
11532
11533
11534
11535
11536
11537
11538
11539
11540
11541
11542
11543
11544
11545
11546
11547
11548
11549
11550
11551
11552
11553
11554
11555
11556
11557
11558
11559
11560
11561
11562
11563
11564
11565
11566
11567
11568
11569
11570
11571
11572
11573
11574
11575
11576
11577
11578
11579
11580
11581
11582
11583
11584
11585
11586
11587
11588
11589
11590
11591
11592
11593
11594
11595
11596
11597
11598
11599
11600
11601
11602
11603
11604
11605
11606
11607
11608
11609
11610
11611
11612
11613
11614
11615
11616
11617
11618
11619
11620
11621
11622
11623
11624
11625
11626
11627
11628
11629
11630
11631
11632
11633
11634
11635
11636
11637
11638
11639
11640
11641
11642
11643
11644
11645
11646
11647
11648
11649
11650
11651
11652
11653
11654
11655
11656
11657
11658
11659
11660
11661
11662
11663
11664
11665
11666
11667
11668
11669
11670
11671
11672
11673
11674
11675
11676
11677
11678
11679
11680
11681
11682
11683
11684
11685
11686
11687
11688
11689
11690
11691
11692
11693
11694
11695
11696
11697
11698
11699
11700
11701
11702
11703
11704
11705
11706
11707
11708
11709
11710
11711
11712
11713
11714
11715
11716
11717
11718
11719
11720
11721
11722
11723
11724
11725
11726
11727
11728
11729
11730
11731
11732
11733
11734
11735
11736
11737
11738
11739
11740
11741
11742
11743
11744
11745
11746
11747
11748
11749
11750
11751
11752
11753
11754
11755
11756
11757
11758
11759
11760
11761
11762
11763
11764
11765
11766
11767
11768
11769
11770
11771
11772
11773
11774
11775
11776
11777
11778
11779
11780
11781
11782
11783
11784
11785
11786
11787
11788
11789
11790
11791
11792
11793
11794
11795
11796
11797
11798
11799
11800
11801
11802
11803
11804
11805
11806
11807
11808
11809
11810
11811
11812
11813
11814
11815
11816
11817
11818
11819
11820
11821
11822
11823
11824
11825
11826
11827
11828
11829
11830
11831
11832
11833
11834
11835
11836
11837
11838
11839
11840
11841
11842
11843
11844
11845
11846
11847
11848
11849
11850
11851
11852
11853
11854
11855
11856
11857
11858
11859
11860
11861
11862
11863
11864
11865
11866
11867
11868
11869
11870
11871
11872
11873
11874
11875
11876
11877
11878
11879
11880
11881
11882
11883
11884
11885
11886
11887
11888
11889
11890
11891
11892
11893
11894
11895
11896
11897
11898
11899
11900
11901
11902
11903
11904
11905
11906
11907
11908
11909
11910
11911
11912
11913
11914
11915
11916
11917
11918
11919
11920
11921
11922
11923
11924
11925
11926
11927
11928
11929
11930
11931
11932
11933
11934
11935
11936
11937
11938
11939
11940
11941
11942
11943
11944
11945
11946
11947
11948
11949
11950
11951
11952
11953
11954
11955
11956
11957
11958
11959
11960
11961
11962
11963
11964
11965
11966
11967
11968
11969
11970
11971
11972
11973
11974
11975
11976
11977
11978
11979
11980
11981
11982
11983
11984
11985
11986
11987
11988
11989
11990
11991
11992
11993
11994
11995
11996
11997
11998
11999
12000
12001
12002
12003
12004
12005
12006
12007
12008
12009
12010
12011
12012
12013
12014
12015
12016
12017
12018
12019
12020
12021
12022
12023
12024
12025
12026
12027
12028
12029
12030
12031
12032
12033
12034
12035
12036
12037
12038
12039
12040
12041
12042
12043
12044
12045
12046
12047
12048
12049
12050
12051
12052
12053
12054
12055
12056
12057
12058
12059
12060
12061
12062
12063
12064
12065
12066
12067
12068
12069
12070
12071
12072
12073
12074
12075
12076
12077
12078
12079
12080
12081
12082
12083
12084
12085
12086
12087
12088
12089
12090
12091
12092
12093
12094
12095
12096
12097
12098
12099
12100
12101
12102
12103
12104
12105
12106
12107
12108
12109
12110
12111
12112
12113
12114
12115
12116
12117
12118
12119
12120
12121
12122
12123
12124
12125
12126
12127
12128
12129
12130
12131
12132
12133
12134
12135
12136
12137
12138
12139
12140
12141
12142
12143
12144
12145
12146
12147
12148
12149
12150
12151
12152
12153
12154
12155
12156
12157
12158
12159
12160
12161
12162
12163
12164
12165
12166
12167
12168
12169
12170
12171
12172
12173
12174
12175
12176
12177
12178
12179
12180
12181
12182
12183
12184
12185
12186
12187
12188
12189
12190
12191
12192
12193
12194
12195
12196
12197
12198
12199
12200
12201
12202
12203
12204
12205
12206
12207
12208
12209
12210
12211
12212
12213
12214
12215
12216
12217
12218
12219
12220
12221
12222
12223
12224
12225
12226
12227
12228
12229
12230
12231
12232
12233
12234
12235
12236
12237
12238
12239
12240
12241
12242
12243
12244
12245
12246
12247
12248
12249
12250
12251
12252
12253
12254
12255
12256
12257
12258
12259
12260
12261
12262
12263
12264
12265
12266
12267
12268
12269
12270
12271
12272
12273
12274
12275
12276
12277
12278
12279
12280
12281
12282
12283
12284
12285
12286
12287
12288
12289
12290
12291
12292
12293
12294
12295
12296
12297
12298
12299
12300
12301
12302
12303
12304
12305
12306
12307
12308
12309
12310
12311
12312
12313
12314
12315
12316
12317
12318
12319
12320
12321
12322
12323
12324
12325
12326
12327
12328
12329
12330
12331
12332
12333
12334
12335
12336
12337
12338
12339
12340
12341
12342
12343
12344
12345
12346
12347
12348
12349
12350
12351
12352
12353
12354
12355
12356
12357
12358
12359
12360
12361
12362
12363
12364
12365
12366
12367
12368
12369
12370
12371
12372
12373
12374
12375
12376
12377
12378
12379
12380
12381
12382
12383
12384
12385
12386
12387
12388
12389
12390
12391
12392
12393
12394
12395
12396
12397
12398
12399
12400
12401
12402
12403
12404
12405
12406
12407
12408
12409
12410
12411
12412
12413
12414
12415
12416
12417
12418
12419
12420
12421
12422
12423
12424
12425
12426
12427
12428
12429
12430
12431
12432
12433
12434
12435
12436
12437
12438
12439
12440
12441
12442
12443
12444
12445
12446
12447
12448
12449
12450
12451
12452
12453
12454
12455
12456
12457
12458
12459
12460
12461
12462
12463
12464
12465
12466
12467
12468
12469
12470
12471
12472
12473
12474
12475
12476
12477
12478
12479
12480
12481
12482
12483
12484
12485
12486
12487
12488
12489
12490
12491
12492
12493
12494
12495
12496
12497
12498
12499
12500
12501
12502
12503
12504
12505
12506
12507
12508
12509
12510
12511
12512
12513
12514
12515
12516
12517
12518
12519
12520
12521
12522
12523
12524
12525
12526
12527
12528
12529
12530
12531
12532
12533
12534
12535
12536
12537
12538
12539
12540
12541
12542
12543
12544
12545
12546
12547
12548
12549
12550
12551
12552
12553
12554
12555
12556
12557
12558
12559
12560
12561
12562
12563
12564
12565
12566
12567
12568
12569
12570
12571
12572
12573
12574
12575
12576
12577
12578
12579
12580
12581
12582
12583
12584
12585
12586
12587
12588
12589
12590
12591
12592
12593
12594
12595
12596
12597
12598
12599
12600
12601
12602
12603
12604
12605
12606
12607
12608
12609
12610
12611
12612
12613
12614
12615
12616
12617
12618
12619
12620
12621
12622
12623
12624
12625
12626
12627
12628
12629
12630
12631
12632
12633
12634
12635
12636
12637
12638
12639
12640
12641
12642
12643
12644
12645
12646
12647
12648
12649
12650
12651
12652
12653
12654
12655
12656
12657
12658
12659
12660
12661
12662
12663
12664
12665
12666
12667
12668
12669
12670
12671
12672
12673
12674
12675
12676
12677
12678
12679
12680
12681
12682
12683
12684
12685
12686
12687
12688
12689
12690
12691
12692
12693
12694
12695
12696
12697
12698
12699
12700
12701
12702
12703
12704
12705
12706
12707
12708
12709
12710
12711
12712
12713
12714
12715
12716
12717
12718
12719
12720
12721
12722
12723
12724
12725
12726
12727
12728
12729
12730
12731
12732
12733
12734
12735
12736
12737
12738
12739
12740
12741
12742
12743
12744
12745
12746
12747
12748
12749
12750
12751
12752
12753
12754
12755
12756
12757
12758
12759
12760
12761
12762
12763
12764
12765
12766
12767
12768
12769
12770
12771
12772
12773
12774
12775
12776
12777
12778
12779
12780
12781
12782
12783
12784
12785
12786
12787
12788
12789
12790
12791
12792
12793
12794
12795
12796
12797
12798
12799
12800
12801
12802
12803
12804
12805
12806
12807
12808
12809
12810
12811
12812
12813
12814
12815
12816
12817
12818
12819
12820
12821
12822
12823
12824
12825
12826
12827
12828
12829
12830
12831
12832
12833
12834
12835
12836
12837
12838
12839
12840
12841
12842
12843
12844
12845
12846
12847
12848
12849
12850
12851
12852
12853
12854
12855
12856
12857
12858
12859
12860
12861
12862
12863
12864
12865
12866
12867
12868
12869
12870
12871
12872
12873
12874
12875
12876
12877
12878
12879
12880
12881
12882
12883
12884
12885
12886
12887
12888
12889
12890
12891
12892
12893
12894
12895
12896
12897
12898
12899
12900
12901
12902
12903
12904
12905
12906
12907
12908
12909
12910
12911
12912
12913
12914
12915
12916
12917
12918
12919
12920
12921
12922
12923
12924
12925
12926
12927
12928
12929
12930
12931
12932
12933
12934
12935
12936
12937
12938
12939
12940
12941
12942
12943
12944
12945
12946
12947
12948
12949
12950
12951
12952
12953
12954
12955
12956
12957
12958
12959
12960
12961
12962
12963
12964
12965
12966
12967
12968
12969
12970
12971
12972
12973
12974
12975
12976
12977
12978
12979
12980
12981
12982
12983
12984
12985
12986
12987
12988
12989
12990
12991
12992
12993
12994
12995
12996
12997
12998
12999
13000
13001
13002
13003
13004
13005
13006
13007
13008
13009
13010
13011
13012
13013
13014
13015
13016
13017
13018
13019
13020
13021
13022
13023
13024
13025
13026
13027
13028
13029
13030
13031
13032
13033
13034
13035
13036
13037
13038
13039
13040
13041
13042
13043
13044
13045
13046
13047
13048
13049
13050
13051
13052
13053
13054
13055
13056
13057
13058
13059
13060
13061
13062
13063
13064
13065
13066
13067
13068
13069
13070
13071
13072
13073
13074
13075
13076
13077
13078
13079
13080
13081
13082
13083
13084
13085
13086
13087
13088
13089
13090
13091
13092
13093
13094
13095
13096
13097
13098
13099
13100
13101
13102
13103
13104
13105
13106
13107
13108
13109
13110
13111
13112
13113
13114
13115
13116
13117
13118
13119
13120
13121
13122
13123
13124
13125
13126
13127
13128
13129
13130
13131
13132
13133
13134
13135
13136
13137
13138
13139
13140
13141
13142
13143
13144
13145
13146
13147
13148
13149
13150
13151
13152
13153
13154
13155
13156
13157
13158
13159
13160
13161
13162
13163
13164
13165
13166
13167
13168
13169
13170
13171
13172
13173
13174
13175
13176
13177
13178
13179
13180
13181
13182
13183
13184
13185
13186
13187
13188
13189
13190
13191
13192
13193
13194
13195
13196
13197
13198
13199
13200
13201
13202
13203
13204
13205
13206
13207
13208
13209
13210
13211
13212
13213
13214
13215
13216
13217
13218
13219
13220
13221
13222
13223
13224
13225
13226
13227
13228
13229
13230
13231
13232
13233
13234
13235
13236
13237
13238
13239
13240
13241
13242
13243
13244
13245
13246
13247
13248
13249
13250
13251
13252
13253
13254
13255
13256
13257
13258
13259
13260
13261
13262
13263
13264
13265
13266
13267
13268
13269
13270
13271
13272
13273
13274
13275
13276
13277
13278
13279
13280
13281
13282
13283
13284
13285
13286
13287
13288
13289
13290
13291
13292
13293
13294
13295
13296
13297
13298
13299
13300
13301
13302
13303
13304
13305
13306
13307
13308
13309
13310
13311
13312
13313
13314
13315
13316
13317
13318
13319
13320
13321
13322
13323
13324
13325
13326
13327
13328
13329
13330
13331
13332
13333
13334
13335
13336
13337
13338
13339
13340
13341
13342
13343
13344
13345
13346
13347
13348
13349
13350
13351
13352
13353
13354
13355
13356
13357
13358
13359
13360
13361
13362
13363
13364
13365
13366
13367
13368
13369
13370
13371
13372
13373
13374
13375
13376
13377
13378
13379
13380
13381
13382
13383
13384
13385
13386
13387
13388
13389
13390
13391
13392
13393
13394
13395
13396
13397
13398
13399
13400
13401
13402
13403
13404
13405
13406
13407
13408
13409
13410
13411
13412
13413
13414
13415
13416
13417
13418
13419
13420
13421
13422
13423
13424
13425
13426
13427
13428
13429
13430
13431
13432
13433
13434
13435
13436
13437
13438
13439
13440
13441
13442
13443
13444
13445
13446
13447
13448
13449
13450
13451
13452
13453
13454
13455
13456
13457
13458
13459
13460
13461
13462
13463
13464
13465
13466
13467
13468
13469
13470
13471
13472
13473
13474
13475
13476
13477
13478
13479
13480
13481
13482
13483
13484
13485
13486
13487
13488
13489
13490
13491
13492
13493
13494
13495
13496
13497
13498
13499
13500
13501
13502
13503
13504
13505
13506
13507
13508
13509
13510
13511
13512
13513
13514
13515
13516
13517
13518
13519
13520
13521
13522
13523
13524
13525
13526
13527
13528
13529
13530
13531
13532
13533
13534
13535
13536
13537
13538
13539
13540
13541
13542
13543
13544
13545
13546
13547
13548
13549
13550
13551
13552
13553
13554
13555
13556
13557
13558
13559
13560
13561
13562
13563
13564
13565
13566
13567
13568
13569
13570
13571
13572
13573
13574
13575
13576
13577
13578
13579
13580
13581
13582
13583
13584
13585
13586
13587
13588
13589
13590
13591
13592
13593
13594
13595
13596
13597
13598
13599
13600
13601
13602
13603
13604
13605
13606
13607
13608
13609
13610
13611
13612
13613
13614
13615
13616
13617
13618
13619
13620
13621
13622
13623
13624
13625
13626
13627
13628
13629
13630
13631
13632
13633
13634
13635
13636
13637
13638
13639
13640
13641
13642
13643
13644
13645
13646
13647
13648
13649
13650
13651
13652
13653
13654
13655
13656
13657
13658
13659
13660
13661
13662
13663
13664
13665
13666
13667
13668
13669
13670
13671
13672
13673
13674
13675
13676
13677
13678
13679
13680
13681
13682
13683
13684
13685
13686
13687
13688
13689
13690
13691
13692
13693
13694
13695
13696
13697
13698
13699
13700
13701
13702
13703
13704
13705
13706
13707
13708
13709
13710
13711
13712
13713
13714
13715
13716
13717
13718
13719
13720
13721
13722
13723
13724
13725
13726
13727
13728
13729
13730
13731
13732
13733
13734
13735
13736
13737
13738
13739
13740
13741
13742
13743
13744
13745
13746
13747
13748
13749
13750
13751
13752
13753
13754
13755
13756
13757
13758
13759
13760
13761
13762
13763
13764
13765
13766
13767
13768
13769
13770
13771
13772
13773
13774
13775
13776
13777
13778
13779
13780
13781
13782
13783
13784
13785
13786
13787
13788
13789
13790
13791
13792
13793
13794
13795
13796
13797
13798
13799
13800
13801
13802
13803
13804
13805
13806
13807
13808
13809
13810
13811
13812
13813
13814
13815
13816
13817
13818
13819
13820
13821
13822
13823
13824
13825
13826
13827
13828
13829
13830
13831
13832
13833
13834
13835
13836
13837
13838
13839
13840
13841
13842
13843
13844
13845
13846
13847
13848
13849
13850
13851
13852
13853
13854
13855
13856
13857
13858
13859
13860
13861
13862
13863
13864
13865
13866
13867
13868
13869
13870
13871
13872
13873
13874
13875
13876
13877
13878
13879
13880
13881
13882
13883
13884
13885
13886
13887
13888
13889
13890
13891
13892
13893
13894
13895
13896
13897
13898
13899
13900
13901
13902
13903
13904
13905
13906
13907
13908
13909
13910
13911
13912
13913
13914
13915
13916
13917
13918
13919
13920
13921
13922
13923
13924
13925
13926
13927
13928
13929
13930
13931
13932
13933
13934
13935
13936
13937
13938
13939
13940
13941
13942
13943
13944
13945
13946
13947
13948
13949
13950
13951
13952
13953
13954
13955
13956
13957
13958
13959
13960
13961
13962
13963
13964
13965
13966
13967
13968
13969
13970
13971
13972
13973
13974
13975
13976
13977
13978
13979
13980
13981
13982
13983
13984
13985
13986
13987
13988
13989
13990
13991
13992
13993
13994
13995
13996
13997
13998
13999
14000
14001
14002
14003
14004
14005
14006
14007
14008
14009
14010
14011
14012
14013
14014
14015
14016
14017
14018
14019
14020
14021
14022
14023
14024
14025
14026
14027
14028
14029
14030
14031
14032
14033
14034
14035
14036
14037
14038
14039
14040
14041
14042
14043
14044
14045
14046
14047
14048
14049
14050
14051
14052
14053
14054
14055
14056
14057
14058
14059
14060
14061
14062
14063
14064
14065
14066
14067
14068
14069
14070
14071
14072
14073
14074
14075
14076
14077
14078
14079
14080
14081
14082
14083
14084
14085
14086
14087
14088
14089
14090
14091
14092
14093
14094
14095
14096
14097
14098
14099
14100
14101
14102
14103
14104
14105
14106
14107
14108
14109
14110
14111
14112
14113
14114
14115
14116
14117
14118
14119
14120
14121
14122
14123
14124
14125
14126
14127
14128
14129
14130
14131
14132
14133
14134
14135
14136
14137
14138
14139
14140
14141
14142
14143
14144
14145
14146
14147
14148
14149
14150
14151
14152
14153
14154
14155
14156
14157
14158
14159
14160
14161
14162
14163
14164
14165
14166
14167
14168
14169
14170
14171
14172
14173
14174
14175
14176
14177
14178
14179
14180
14181
14182
14183
14184
14185
14186
14187
14188
14189
14190
14191
14192
14193
14194
14195
14196
14197
14198
14199
14200
14201
14202
14203
14204
14205
14206
14207
14208
14209
14210
14211
14212
14213
14214
14215
14216
14217
14218
14219
14220
14221
14222
14223
14224
14225
14226
14227
14228
14229
14230
14231
14232
14233
14234
14235
14236
14237
14238
14239
14240
14241
14242
14243
14244
14245
14246
14247
14248
14249
14250
14251
14252
14253
14254
14255
14256
14257
14258
14259
14260
14261
14262
14263
14264
14265
14266
14267
14268
14269
14270
14271
14272
14273
14274
14275
14276
14277
14278
14279
14280
14281
14282
14283
14284
14285
14286
14287
14288
14289
14290
14291
14292
14293
14294
14295
14296
14297
14298
14299
14300
14301
14302
14303
14304
14305
14306
14307
14308
14309
14310
14311
14312
14313
14314
14315
14316
14317
14318
14319
14320
14321
14322
14323
14324
14325
14326
14327
14328
14329
14330
14331
14332
14333
14334
14335
14336
14337
14338
14339
14340
14341
14342
14343
14344
14345
14346
14347
14348
14349
14350
14351
14352
14353
14354
14355
14356
14357
14358
14359
14360
14361
14362
14363
14364
14365
14366
14367
14368
14369
14370
14371
14372
14373
14374
14375
14376
14377
14378
14379
14380
14381
14382
14383
14384
14385
14386
14387
14388
14389
14390
14391
14392
14393
14394
14395
14396
14397
14398
14399
14400
14401
14402
14403
14404
14405
14406
14407
14408
14409
14410
14411
14412
14413
14414
14415
14416
14417
14418
14419
14420
14421
14422
14423
14424
14425
14426
14427
14428
14429
14430
14431
14432
14433
14434
14435
14436
14437
14438
14439
14440
14441
14442
14443
14444
14445
14446
14447
14448
14449
14450
14451
14452
14453
14454
14455
14456
14457
14458
14459
14460
14461
14462
14463
14464
14465
14466
14467
14468
14469
14470
14471
14472
14473
14474
14475
14476
14477
14478
14479
14480
14481
14482
14483
14484
14485
14486
14487
14488
14489
14490
14491
14492
14493
14494
14495
14496
14497
14498
14499
14500
14501
14502
14503
14504
14505
14506
14507
14508
14509
14510
14511
14512
14513
14514
14515
14516
14517
14518
14519
14520
14521
14522
14523
14524
14525
14526
14527
14528
14529
14530
14531
14532
14533
14534
14535
14536
14537
14538
14539
14540
14541
14542
14543
14544
14545
14546
14547
14548
14549
14550
14551
14552
14553
14554
14555
14556
14557
14558
14559
14560
14561
14562
14563
14564
14565
14566
14567
14568
14569
14570
14571
14572
14573
14574
14575
14576
14577
14578
14579
14580
14581
14582
14583
14584
14585
14586
14587
14588
14589
14590
14591
14592
14593
14594
14595
14596
14597
14598
14599
14600
14601
14602
14603
14604
14605
14606
14607
14608
14609
14610
14611
14612
14613
14614
14615
14616
14617
14618
14619
14620
14621
14622
14623
14624
14625
14626
14627
14628
14629
14630
14631
14632
14633
14634
14635
14636
14637
14638
14639
14640
14641
14642
14643
14644
14645
14646
14647
14648
14649
14650
14651
14652
14653
14654
14655
14656
14657
14658
14659
14660
14661
14662
14663
14664
14665
14666
14667
14668
14669
14670
14671
14672
14673
14674
14675
14676
14677
14678
14679
14680
14681
14682
14683
14684
14685
14686
14687
14688
14689
14690
14691
14692
14693
14694
14695
14696
14697
14698
14699
14700
14701
14702
14703
14704
14705
14706
14707
14708
14709
14710
14711
14712
14713
14714
14715
14716
14717
14718
14719
14720
14721
14722
14723
14724
14725
14726
14727
14728
14729
14730
14731
14732
14733
14734
14735
14736
14737
14738
14739
14740
14741
14742
14743
14744
14745
14746
14747
14748
14749
14750
14751
14752
14753
14754
14755
14756
14757
14758
14759
14760
14761
14762
14763
14764
14765
14766
14767
14768
14769
14770
14771
14772
14773
14774
14775
14776
14777
14778
14779
14780
14781
14782
14783
14784
14785
14786
14787
14788
14789
14790
14791
14792
14793
14794
14795
14796
14797
14798
14799
14800
14801
14802
14803
14804
14805
14806
14807
14808
14809
14810
14811
14812
14813
14814
14815
14816
14817
14818
14819
14820
14821
14822
14823
14824
14825
14826
14827
14828
14829
14830
14831
14832
14833
14834
14835
14836
14837
14838
14839
14840
14841
14842
14843
14844
14845
14846
14847
14848
14849
14850
14851
14852
14853
14854
14855
14856
14857
14858
14859
14860
14861
14862
14863
14864
14865
14866
14867
14868
14869
14870
14871
14872
14873
14874
14875
14876
14877
14878
14879
14880
14881
14882
14883
14884
14885
14886
14887
14888
14889
14890
14891
14892
14893
14894
14895
14896
14897
14898
14899
14900
14901
14902
14903
14904
14905
14906
14907
14908
14909
14910
14911
14912
14913
14914
14915
14916
14917
14918
14919
14920
14921
14922
14923
14924
14925
14926
14927
14928
14929
14930
14931
14932
14933
14934
14935
14936
14937
14938
14939
14940
14941
14942
14943
14944
14945
14946
14947
14948
14949
14950
14951
14952
14953
14954
14955
14956
14957
14958
14959
14960
14961
14962
14963
14964
14965
14966
14967
14968
14969
14970
14971
14972
14973
14974
14975
14976
14977
14978
14979
14980
14981
14982
14983
14984
14985
14986
14987
14988
14989
14990
14991
14992
14993
14994
14995
14996
14997
14998
14999
15000
15001
15002
15003
15004
15005
15006
15007
15008
15009
15010
15011
15012
15013
15014
15015
15016
15017
15018
15019
15020
15021
15022
15023
15024
15025
15026
15027
15028
15029
15030
15031
15032
15033
15034
15035
15036
15037
15038
15039
15040
15041
15042
15043
15044
15045
15046
15047
15048
15049
15050
15051
15052
15053
15054
15055
15056
15057
15058
15059
15060
15061
15062
15063
15064
15065
15066
15067
15068
15069
15070
15071
15072
15073
15074
15075
15076
15077
15078
15079
15080
15081
15082
15083
15084
15085
15086
15087
15088
15089
15090
15091
15092
15093
15094
15095
15096
15097
15098
15099
15100
15101
15102
15103
15104
15105
15106
15107
15108
15109
15110
15111
15112
15113
15114
15115
15116
15117
15118
15119
15120
15121
15122
15123
15124
15125
15126
15127
15128
15129
15130
15131
15132
15133
15134
15135
15136
15137
15138
15139
15140
15141
15142
15143
15144
15145
15146
15147
15148
15149
15150
15151
15152
15153
15154
15155
15156
15157
15158
15159
15160
15161
15162
15163
15164
15165
15166
15167
15168
15169
15170
15171
15172
15173
15174
15175
15176
15177
15178
15179
15180
15181
15182
15183
15184
15185
15186
15187
15188
15189
15190
15191
15192
15193
15194
15195
15196
15197
15198
15199
15200
15201
15202
15203
15204
15205
15206
15207
15208
15209
15210
15211
15212
15213
15214
15215
15216
15217
15218
15219
15220
15221
15222
15223
15224
15225
15226
15227
15228
15229
15230
15231
15232
15233
15234
15235
15236
15237
15238
15239
15240
15241
15242
15243
15244
15245
15246
15247
15248
15249
15250
15251
15252
15253
15254
15255
15256
15257
15258
15259
15260
15261
15262
15263
15264
15265
15266
15267
15268
15269
15270
15271
15272
15273
15274
15275
15276
15277
15278
15279
15280
15281
15282
15283
15284
15285
15286
15287
15288
15289
15290
15291
15292
15293
15294
15295
15296
15297
15298
15299
15300
15301
15302
15303
15304
15305
15306
15307
15308
15309
15310
15311
15312
15313
15314
15315
15316
15317
15318
15319
15320
15321
15322
15323
15324
15325
15326
15327
15328
15329
15330
15331
15332
15333
15334
15335
15336
15337
15338
15339
15340
15341
15342
15343
15344
15345
15346
15347
15348
15349
15350
15351
15352
15353
15354
15355
15356
15357
15358
15359
15360
15361
15362
15363
15364
15365
15366
15367
15368
15369
15370
15371
15372
15373
15374
15375
15376
15377
15378
15379
15380
15381
15382
15383
15384
15385
15386
15387
15388
15389
15390
15391
15392
15393
15394
15395
15396
15397
15398
15399
15400
15401
15402
15403
15404
15405
15406
15407
15408
15409
15410
15411
15412
15413
15414
15415
15416
15417
15418
15419
15420
15421
15422
15423
15424
15425
15426
15427
15428
15429
15430
15431
15432
15433
15434
15435
15436
15437
15438
15439
15440
15441
15442
15443
15444
15445
15446
15447
15448
15449
15450
15451
15452
15453
15454
15455
15456
15457
15458
15459
15460
15461
15462
15463
15464
15465
15466
15467
15468
15469
15470
15471
15472
15473
15474
15475
15476
15477
15478
15479
15480
15481
15482
15483
15484
15485
15486
15487
15488
15489
15490
15491
15492
15493
15494
15495
15496
15497
15498
15499
15500
15501
15502
15503
15504
15505
15506
15507
15508
15509
15510
15511
15512
15513
15514
15515
15516
15517
15518
15519
15520
15521
15522
15523
15524
15525
15526
15527
15528
15529
15530
15531
15532
15533
15534
15535
15536
15537
15538
15539
15540
15541
15542
15543
15544
15545
15546
15547
15548
15549
15550
15551
15552
15553
15554
15555
15556
15557
15558
15559
15560
15561
15562
15563
15564
15565
15566
15567
15568
15569
15570
15571
15572
15573
15574
15575
15576
15577
15578
15579
15580
15581
15582
15583
15584
15585
15586
15587
15588
15589
15590
15591
15592
15593
15594
15595
15596
15597
15598
15599
15600
15601
15602
15603
15604
15605
15606
15607
15608
15609
15610
15611
15612
15613
15614
15615
15616
15617
15618
15619
15620
15621
15622
15623
15624
15625
15626
15627
15628
15629
15630
15631
15632
15633
15634
15635
15636
15637
15638
15639
15640
15641
15642
15643
15644
15645
15646
15647
15648
15649
15650
15651
15652
15653
15654
15655
15656
15657
15658
15659
15660
15661
15662
15663
15664
15665
15666
15667
15668
15669
15670
15671
15672
15673
15674
15675
15676
15677
15678
15679
15680
15681
15682
15683
15684
15685
15686
15687
15688
15689
15690
15691
15692
15693
15694
15695
15696
15697
15698
15699
15700
15701
15702
15703
15704
15705
15706
15707
15708
15709
15710
15711
15712
15713
15714
15715
15716
15717
15718
15719
15720
15721
15722
15723
15724
15725
15726
15727
15728
15729
15730
15731
15732
15733
15734
15735
15736
15737
15738
15739
15740
15741
15742
15743
15744
15745
15746
15747
15748
15749
15750
15751
15752
15753
15754
15755
15756
15757
15758
15759
15760
15761
15762
15763
15764
15765
15766
15767
15768
15769
15770
15771
15772
15773
15774
15775
15776
15777
15778
15779
15780
15781
15782
15783
15784
15785
15786
15787
15788
15789
15790
15791
15792
15793
15794
15795
15796
15797
15798
15799
15800
15801
15802
15803
15804
15805
15806
15807
15808
15809
15810
15811
15812
15813
15814
15815
15816
15817
15818
15819
15820
15821
15822
15823
15824
15825
15826
15827
15828
15829
15830
15831
15832
15833
15834
15835
15836
15837
15838
15839
15840
15841
15842
15843
15844
15845
15846
15847
15848
15849
15850
15851
15852
15853
15854
15855
15856
15857
15858
15859
15860
15861
15862
15863
15864
15865
15866
15867
15868
15869
15870
15871
15872
15873
15874
15875
15876
15877
15878
15879
15880
15881
15882
15883
15884
15885
15886
15887
15888
15889
15890
15891
15892
15893
15894
15895
15896
15897
15898
15899
15900
15901
15902
15903
15904
15905
15906
15907
15908
15909
15910
15911
15912
15913
15914
15915
15916
15917
15918
15919
15920
15921
15922
15923
15924
15925
15926
15927
15928
15929
15930
15931
15932
15933
15934
15935
15936
15937
15938
15939
15940
15941
15942
15943
15944
15945
15946
15947
15948
15949
15950
15951
15952
15953
15954
15955
15956
15957
15958
15959
15960
15961
15962
15963
15964
15965
15966
15967
15968
15969
15970
15971
15972
15973
15974
15975
15976
15977
15978
15979
15980
15981
15982
15983
15984
15985
15986
15987
15988
15989
15990
15991
15992
15993
15994
15995
15996
15997
15998
15999
16000
16001
16002
16003
16004
16005
16006
16007
16008
16009
16010
16011
16012
16013
16014
16015
16016
16017
16018
16019
16020
16021
16022
16023
16024
16025
16026
16027
16028
16029
16030
16031
16032
16033
16034
16035
16036
16037
16038
16039
16040
16041
16042
16043
16044
16045
16046
16047
16048
16049
16050
16051
16052
16053
16054
16055
16056
16057
16058
16059
16060
16061
16062
16063
16064
16065
16066
16067
16068
16069
16070
16071
16072
16073
16074
16075
16076
16077
16078
16079
16080
16081
16082
16083
16084
16085
16086
16087
16088
16089
16090
16091
16092
16093
16094
16095
16096
16097
16098
16099
16100
16101
16102
16103
16104
16105
16106
16107
16108
16109
16110
16111
16112
16113
16114
16115
16116
16117
16118
16119
16120
16121
16122
16123
16124
16125
16126
16127
16128
16129
16130
16131
16132
16133
16134
16135
16136
16137
16138
16139
16140
16141
16142
16143
16144
16145
16146
16147
16148
16149
16150
16151
16152
16153
16154
16155
16156
16157
16158
16159
16160
16161
16162
16163
16164
16165
16166
16167
16168
16169
16170
16171
16172
16173
16174
16175
16176
16177
16178
16179
16180
16181
16182
16183
16184
16185
16186
16187
16188
16189
16190
16191
16192
16193
16194
16195
16196
16197
16198
16199
16200
16201
16202
16203
16204
16205
16206
16207
16208
16209
16210
16211
16212
16213
16214
16215
16216
16217
16218
16219
16220
16221
16222
16223
16224
16225
16226
16227
16228
16229
16230
16231
16232
16233
16234
16235
16236
16237
16238
16239
16240
16241
16242
16243
16244
16245
16246
16247
16248
16249
16250
16251
16252
16253
16254
16255
16256
16257
16258
16259
16260
16261
16262
16263
16264
16265
16266
16267
16268
16269
16270
16271
16272
16273
16274
16275
16276
16277
16278
16279
16280
16281
16282
16283
16284
16285
16286
16287
16288
16289
16290
16291
16292
16293
16294
16295
16296
16297
16298
16299
16300
16301
16302
16303
16304
16305
16306
16307
16308
16309
16310
16311
16312
16313
16314
16315
16316
16317
16318
16319
16320
16321
16322
16323
16324
16325
16326
16327
16328
16329
16330
16331
16332
16333
16334
16335
16336
16337
16338
16339
16340
16341
16342
16343
16344
16345
16346
16347
16348
16349
16350
16351
16352
16353
16354
16355
16356
16357
16358
16359
16360
16361
16362
16363
16364
16365
16366
16367
16368
16369
16370
16371
16372
16373
16374
16375
16376
16377
16378
16379
16380
16381
16382
16383
16384
16385
16386
16387
16388
16389
16390
16391
16392
16393
16394
16395
16396
16397
16398
16399
16400
16401
16402
16403
16404
16405
16406
16407
16408
16409
16410
16411
16412
16413
16414
16415
16416
16417
16418
16419
16420
16421
16422
16423
16424
16425
16426
16427
16428
16429
16430
16431
16432
16433
16434
16435
16436
16437
16438
16439
16440
16441
16442
16443
16444
16445
16446
16447
16448
16449
16450
16451
16452
16453
16454
16455
16456
16457
16458
16459
16460
16461
16462
16463
16464
16465
16466
16467
16468
16469
16470
16471
16472
16473
16474
16475
16476
16477
16478
16479
16480
16481
16482
16483
16484
16485
16486
16487
16488
16489
16490
16491
16492
16493
16494
16495
16496
16497
16498
16499
16500
16501
16502
16503
16504
16505
16506
16507
16508
16509
16510
16511
16512
16513
16514
16515
16516
16517
16518
16519
16520
16521
16522
16523
16524
16525
16526
16527
16528
16529
16530
16531
16532
16533
16534
16535
16536
16537
16538
16539
16540
16541
16542
16543
16544
16545
16546
16547
16548
16549
16550
16551
16552
16553
16554
16555
16556
16557
16558
16559
16560
16561
16562
16563
16564
16565
16566
16567
16568
16569
16570
16571
16572
16573
16574
16575
16576
16577
16578
16579
16580
16581
16582
16583
16584
16585
16586
16587
16588
16589
16590
16591
16592
16593
16594
16595
16596
16597
16598
16599
16600
16601
16602
16603
16604
16605
16606
16607
16608
16609
16610
16611
16612
16613
16614
16615
16616
16617
16618
16619
16620
16621
16622
16623
16624
16625
16626
16627
16628
16629
16630
16631
16632
16633
16634
16635
16636
16637
16638
16639
16640
16641
16642
16643
16644
16645
16646
16647
16648
16649
16650
16651
16652
16653
16654
16655
16656
16657
16658
16659
16660
16661
16662
16663
16664
16665
16666
16667
16668
16669
16670
16671
16672
16673
16674
16675
16676
16677
16678
16679
16680
16681
16682
16683
16684
16685
16686
16687
16688
16689
16690
16691
16692
16693
16694
16695
16696
16697
16698
16699
16700
16701
16702
16703
16704
16705
16706
16707
16708
16709
16710
16711
16712
16713
16714
16715
16716
16717
16718
16719
16720
16721
16722
16723
16724
16725
16726
16727
16728
16729
16730
16731
16732
16733
16734
16735
16736
16737
16738
16739
16740
16741
16742
16743
16744
16745
16746
16747
16748
16749
16750
16751
16752
16753
16754
16755
16756
16757
16758
16759
16760
16761
16762
16763
16764
16765
16766
16767
16768
16769
16770
16771
16772
16773
16774
16775
16776
16777
16778
16779
16780
16781
16782
16783
16784
16785
16786
16787
16788
16789
16790
16791
16792
16793
16794
16795
16796
16797
16798
16799
16800
16801
16802
16803
16804
16805
16806
16807
16808
16809
16810
16811
16812
16813
16814
16815
16816
16817
16818
16819
16820
16821
16822
16823
16824
16825
16826
16827
16828
16829
16830
16831
16832
16833
16834
16835
16836
16837
16838
16839
16840
16841
16842
16843
16844
16845
16846
16847
16848
16849
16850
16851
16852
16853
16854
16855
16856
16857
16858
16859
16860
16861
16862
16863
16864
16865
16866
16867
16868
16869
16870
16871
16872
16873
16874
16875
16876
16877
16878
16879
16880
16881
16882
16883
16884
16885
16886
16887
16888
16889
16890
16891
16892
16893
16894
16895
16896
16897
16898
16899
16900
16901
16902
16903
16904
16905
16906
16907
16908
16909
16910
16911
16912
16913
16914
16915
16916
16917
16918
16919
16920
16921
16922
16923
16924
16925
16926
16927
16928
16929
16930
16931
16932
16933
16934
16935
16936
16937
16938
16939
16940
16941
16942
16943
16944
16945
16946
16947
16948
16949
16950
16951
16952
16953
16954
16955
16956
16957
16958
16959
16960
16961
16962
16963
16964
16965
16966
16967
16968
16969
16970
16971
16972
16973
16974
16975
16976
16977
16978
16979
16980
16981
16982
16983
16984
16985
16986
16987
16988
16989
16990
16991
16992
16993
16994
16995
16996
16997
16998
16999
17000
17001
17002
17003
17004
17005
17006
17007
17008
17009
17010
17011
17012
17013
17014
17015
17016
17017
17018
17019
17020
17021
17022
17023
17024
17025
17026
17027
17028
17029
17030
17031
17032
17033
17034
17035
17036
17037
17038
17039
17040
17041
17042
17043
17044
17045
17046
17047
17048
17049
17050
17051
17052
17053
17054
17055
17056
17057
17058
17059
17060
17061
17062
17063
17064
17065
17066
17067
17068
17069
17070
17071
17072
17073
17074
17075
17076
17077
17078
17079
17080
17081
17082
17083
17084
17085
17086
17087
17088
17089
17090
17091
17092
17093
17094
17095
17096
17097
17098
17099
17100
17101
17102
17103
17104
17105
17106
17107
17108
17109
17110
17111
17112
17113
17114
17115
17116
17117
17118
17119
17120
17121
17122
17123
17124
17125
17126
17127
17128
17129
17130
17131
17132
17133
17134
17135
17136
17137
17138
17139
17140
17141
17142
17143
17144
17145
17146
17147
17148
17149
17150
17151
17152
17153
17154
17155
17156
17157
17158
17159
17160
17161
17162
17163
17164
17165
17166
17167
17168
17169
17170
17171
17172
17173
17174
17175
17176
17177
17178
17179
17180
17181
17182
17183
17184
17185
17186
17187
17188
17189
17190
17191
17192
17193
17194
17195
17196
17197
17198
17199
17200
17201
17202
17203
17204
17205
17206
17207
17208
17209
17210
17211
17212
17213
17214
17215
17216
17217
17218
17219
17220
17221
17222
17223
17224
17225
17226
17227
17228
17229
17230
17231
17232
17233
17234
17235
17236
17237
17238
17239
17240
17241
17242
17243
17244
17245
17246
17247
17248
17249
17250
17251
17252
17253
17254
17255
17256
17257
17258
17259
17260
17261
17262
17263
17264
17265
17266
17267
17268
17269
17270
17271
17272
17273
17274
17275
17276
17277
17278
17279
17280
17281
17282
17283
17284
17285
17286
17287
17288
17289
17290
17291
17292
17293
17294
17295
17296
17297
17298
17299
17300
17301
17302
17303
17304
17305
17306
17307
17308
17309
17310
17311
17312
17313
17314
17315
17316
17317
17318
17319
17320
17321
17322
17323
17324
17325
17326
17327
17328
17329
17330
17331
17332
17333
17334
17335
17336
17337
17338
17339
17340
17341
17342
17343
17344
17345
17346
17347
17348
17349
17350
17351
17352
17353
17354
17355
17356
17357
17358
17359
17360
17361
17362
17363
17364
17365
17366
17367
17368
17369
17370
17371
17372
17373
17374
17375
17376
17377
17378
17379
17380
17381
17382
17383
17384
17385
17386
17387
17388
17389
17390
17391
17392
17393
17394
17395
17396
17397
17398
17399
17400
17401
17402
17403
17404
17405
17406
17407
17408
17409
17410
17411
17412
17413
17414
17415
17416
17417
17418
17419
17420
17421
17422
17423
17424
17425
17426
17427
17428
17429
17430
17431
17432
17433
17434
17435
17436
17437
17438
17439
17440
17441
17442
17443
17444
17445
17446
17447
17448
17449
17450
17451
17452
17453
17454
17455
17456
17457
17458
17459
17460
17461
17462
17463
17464
17465
17466
17467
17468
17469
17470
17471
17472
17473
17474
17475
17476
17477
17478
17479
17480
17481
17482
17483
17484
17485
17486
17487
17488
17489
17490
17491
17492
17493
17494
17495
17496
17497
17498
17499
17500
17501
17502
17503
17504
17505
17506
17507
17508
17509
17510
17511
17512
17513
17514
17515
17516
17517
17518
17519
17520
17521
17522
17523
17524
17525
17526
17527
17528
17529
17530
17531
17532
17533
17534
17535
17536
17537
17538
17539
17540
17541
17542
17543
17544
17545
17546
17547
17548
17549
17550
17551
17552
17553
17554
17555
17556
17557
17558
17559
17560
17561
17562
17563
17564
17565
17566
17567
17568
17569
17570
17571
17572
17573
17574
17575
17576
17577
17578
17579
17580
17581
17582
17583
17584
17585
17586
17587
17588
17589
17590
17591
17592
17593
17594
17595
17596
17597
17598
17599
17600
17601
17602
17603
17604
17605
17606
17607
17608
17609
17610
17611
17612
17613
17614
17615
17616
17617
17618
17619
17620
17621
17622
17623
17624
17625
17626
17627
17628
17629
17630
17631
17632
17633
17634
17635
17636
17637
17638
17639
17640
17641
17642
17643
17644
17645
17646
17647
17648
17649
17650
17651
17652
17653
17654
17655
17656
17657
17658
17659
17660
17661
17662
17663
17664
17665
17666
17667
17668
17669
17670
17671
17672
17673
17674
17675
17676
17677
17678
17679
17680
17681
17682
17683
17684
17685
17686
17687
17688
17689
17690
17691
17692
17693
17694
17695
17696
17697
17698
17699
17700
17701
17702
17703
17704
17705
17706
17707
17708
17709
17710
17711
17712
17713
17714
17715
17716
17717
17718
17719
17720
17721
17722
17723
17724
17725
17726
17727
17728
17729
17730
17731
17732
17733
17734
17735
17736
17737
17738
17739
17740
17741
17742
17743
17744
17745
17746
17747
17748
17749
17750
17751
17752
17753
17754
17755
17756
17757
17758
17759
17760
17761
17762
17763
17764
17765
17766
17767
17768
17769
17770
17771
17772
17773
17774
17775
17776
17777
17778
17779
17780
17781
17782
17783
17784
17785
17786
17787
17788
17789
17790
17791
17792
17793
17794
17795
17796
17797
17798
17799
17800
17801
17802
17803
17804
17805
17806
17807
17808
17809
17810
17811
17812
17813
17814
17815
17816
17817
17818
17819
17820
17821
17822
17823
17824
17825
17826
17827
17828
17829
17830
17831
17832
17833
17834
17835
17836
17837
17838
17839
17840
17841
17842
17843
17844
17845
17846
17847
17848
17849
17850
17851
17852
17853
17854
17855
17856
17857
17858
17859
17860
17861
17862
17863
17864
17865
17866
17867
17868
17869
17870
17871
17872
17873
17874
17875
17876
17877
17878
17879
17880
17881
17882
17883
17884
17885
17886
17887
17888
17889
17890
17891
17892
17893
17894
17895
17896
17897
17898
17899
17900
17901
17902
17903
17904
17905
17906
17907
17908
17909
17910
17911
17912
17913
17914
17915
17916
17917
17918
17919
17920
17921
17922
17923
17924
17925
17926
17927
17928
17929
17930
17931
17932
17933
17934
17935
17936
17937
17938
17939
17940
17941
17942
17943
17944
17945
17946
17947
17948
17949
17950
17951
17952
17953
17954
17955
17956
17957
17958
17959
17960
17961
17962
17963
17964
17965
17966
17967
17968
17969
17970
17971
17972
17973
17974
17975
17976
17977
17978
17979
17980
17981
17982
17983
17984
17985
17986
17987
17988
17989
17990
17991
17992
17993
17994
17995
17996
17997
17998
17999
18000
18001
18002
18003
18004
18005
18006
18007
18008
18009
18010
18011
18012
18013
18014
18015
18016
18017
18018
18019
18020
18021
18022
18023
18024
18025
18026
18027
18028
18029
18030
18031
18032
18033
18034
18035
18036
18037
18038
18039
18040
18041
18042
18043
18044
18045
18046
18047
18048
18049
18050
18051
18052
18053
18054
18055
18056
18057
18058
18059
18060
18061
18062
18063
18064
18065
18066
18067
18068
18069
18070
18071
18072
18073
18074
18075
18076
18077
18078
18079
18080
18081
18082
18083
18084
18085
18086
18087
18088
18089
18090
18091
18092
18093
18094
18095
18096
18097
18098
18099
18100
18101
18102
18103
18104
18105
18106
18107
18108
18109
18110
18111
18112
18113
18114
18115
18116
18117
18118
18119
18120
18121
18122
18123
18124
18125
18126
18127
18128
18129
18130
18131
18132
18133
18134
18135
18136
18137
18138
18139
18140
18141
18142
18143
18144
18145
18146
18147
18148
18149
18150
18151
18152
18153
18154
18155
18156
18157
18158
18159
18160
18161
18162
18163
18164
18165
18166
18167
18168
18169
18170
18171
18172
18173
18174
18175
18176
18177
18178
18179
18180
18181
18182
18183
18184
18185
18186
18187
18188
18189
18190
18191
18192
18193
18194
18195
18196
18197
18198
18199
18200
18201
18202
18203
18204
18205
18206
18207
18208
18209
18210
18211
18212
18213
18214
18215
18216
18217
18218
18219
18220
18221
18222
18223
18224
18225
18226
18227
18228
18229
18230
18231
18232
18233
18234
18235
18236
18237
18238
18239
18240
18241
18242
18243
18244
18245
18246
18247
18248
18249
18250
18251
18252
18253
18254
18255
18256
18257
18258
18259
18260
18261
18262
18263
18264
18265
18266
18267
18268
18269
18270
18271
18272
18273
18274
18275
18276
18277
18278
18279
18280
18281
18282
18283
18284
18285
18286
18287
18288
18289
18290
18291
18292
18293
18294
18295
18296
18297
18298
18299
18300
18301
18302
18303
18304
18305
18306
18307
18308
18309
18310
18311
18312
18313
18314
18315
18316
18317
18318
18319
18320
18321
18322
18323
18324
18325
18326
18327
18328
18329
18330
18331
18332
18333
18334
18335
18336
18337
18338
18339
18340
18341
18342
18343
18344
18345
18346
18347
18348
18349
18350
18351
18352
18353
18354
18355
18356
18357
18358
18359
18360
18361
18362
18363
18364
18365
18366
18367
18368
18369
18370
18371
18372
18373
18374
18375
18376
18377
18378
18379
18380
18381
18382
18383
18384
18385
18386
18387
18388
18389
18390
18391
18392
18393
18394
18395
18396
18397
18398
18399
18400
18401
18402
18403
18404
18405
18406
18407
18408
18409
18410
18411
18412
18413
18414
18415
18416
18417
18418
18419
18420
18421
18422
18423
18424
18425
18426
18427
18428
18429
18430
18431
18432
18433
18434
18435
18436
18437
18438
18439
18440
18441
18442
18443
18444
18445
18446
18447
18448
18449
18450
18451
18452
18453
18454
18455
18456
18457
18458
18459
18460
18461
18462
18463
18464
18465
18466
18467
18468
18469
18470
18471
18472
18473
18474
18475
18476
18477
18478
18479
18480
18481
18482
18483
18484
18485
18486
18487
18488
18489
18490
18491
18492
18493
18494
18495
18496
18497
18498
18499
18500
18501
18502
18503
18504
18505
18506
18507
18508
18509
18510
18511
18512
18513
18514
18515
18516
18517
18518
18519
18520
18521
18522
18523
18524
18525
18526
18527
18528
18529
18530
18531
18532
18533
18534
18535
18536
18537
18538
18539
18540
18541
18542
18543
18544
18545
18546
18547
18548
18549
18550
18551
18552
18553
18554
18555
18556
18557
18558
18559
18560
18561
18562
18563
18564
18565
18566
18567
18568
18569
18570
18571
18572
18573
18574
18575
18576
18577
18578
18579
18580
18581
18582
18583
18584
18585
18586
18587
18588
18589
18590
18591
18592
18593
18594
18595
18596
18597
18598
18599
18600
18601
18602
18603
18604
18605
18606
18607
18608
18609
18610
18611
18612
18613
18614
18615
18616
18617
18618
18619
18620
18621
18622
18623
18624
18625
18626
18627
18628
18629
18630
18631
18632
18633
18634
18635
18636
18637
18638
18639
18640
18641
18642
18643
18644
18645
18646
18647
18648
18649
18650
18651
18652
18653
18654
18655
18656
18657
18658
18659
18660
18661
18662
18663
18664
18665
18666
18667
18668
18669
18670
18671
18672
18673
18674
18675
18676
18677
18678
18679
18680
18681
18682
18683
18684
18685
18686
18687
18688
18689
18690
18691
18692
18693
18694
18695
18696
18697
18698
18699
18700
18701
18702
18703
18704
18705
18706
18707
18708
18709
18710
18711
18712
18713
18714
18715
18716
18717
18718
18719
18720
18721
18722
18723
18724
18725
18726
18727
18728
18729
18730
18731
18732
18733
18734
18735
18736
18737
18738
18739
18740
18741
18742
18743
18744
18745
18746
18747
18748
18749
18750
18751
18752
18753
18754
18755
18756
18757
18758
18759
18760
18761
18762
18763
18764
18765
18766
18767
18768
18769
18770
18771
18772
18773
18774
18775
18776
18777
18778
18779
18780
18781
18782
18783
18784
18785
18786
18787
18788
18789
18790
18791
18792
18793
18794
18795
18796
18797
18798
18799
18800
18801
18802
18803
18804
18805
18806
18807
18808
18809
18810
18811
18812
18813
18814
18815
18816
18817
18818
18819
18820
18821
18822
18823
18824
18825
18826
18827
18828
18829
18830
18831
18832
18833
18834
18835
18836
18837
18838
18839
18840
18841
18842
18843
18844
18845
18846
18847
18848
18849
18850
18851
18852
18853
18854
18855
18856
18857
18858
18859
18860
18861
18862
18863
18864
18865
18866
18867
18868
18869
18870
18871
18872
18873
18874
18875
18876
18877
18878
18879
18880
18881
18882
18883
18884
18885
18886
18887
18888
18889
18890
18891
18892
18893
18894
18895
18896
18897
18898
18899
18900
18901
18902
18903
18904
18905
18906
18907
18908
18909
18910
18911
18912
18913
18914
18915
18916
18917
18918
18919
18920
18921
18922
18923
18924
18925
18926
18927
18928
18929
18930
18931
18932
18933
18934
18935
18936
18937
18938
18939
18940
18941
18942
18943
18944
18945
18946
18947
18948
18949
18950
18951
18952
18953
18954
18955
18956
18957
18958
18959
18960
18961
18962
18963
18964
18965
18966
18967
18968
18969
18970
18971
18972
18973
18974
18975
18976
18977
18978
18979
18980
18981
18982
18983
18984
18985
18986
18987
18988
18989
18990
18991
18992
18993
18994
18995
18996
18997
18998
18999
19000
19001
19002
19003
19004
19005
19006
19007
19008
19009
19010
19011
19012
19013
19014
19015
19016
19017
19018
19019
19020
19021
19022
19023
19024
19025
19026
19027
19028
19029
19030
19031
19032
19033
19034
19035
19036
19037
19038
19039
19040
19041
19042
19043
19044
19045
19046
19047
19048
19049
19050
19051
19052
19053
19054
19055
19056
19057
19058
19059
19060
19061
19062
19063
19064
19065
19066
19067
19068
19069
19070
19071
19072
19073
19074
19075
19076
19077
19078
19079
19080
19081
19082
19083
19084
19085
19086
19087
19088
19089
19090
19091
19092
19093
19094
19095
19096
19097
19098
19099
19100
19101
19102
19103
19104
19105
19106
19107
19108
19109
19110
19111
19112
19113
19114
19115
19116
19117
19118
19119
19120
19121
19122
19123
19124
19125
19126
19127
19128
19129
19130
19131
19132
19133
19134
19135
19136
19137
19138
19139
19140
19141
19142
19143
19144
19145
19146
19147
19148
19149
19150
19151
19152
19153
19154
19155
19156
19157
19158
19159
19160
19161
19162
19163
19164
19165
19166
19167
19168
19169
19170
19171
19172
19173
19174
19175
19176
19177
19178
19179
19180
19181
19182
19183
19184
19185
19186
19187
19188
19189
19190
19191
19192
19193
19194
19195
19196
19197
19198
19199
19200
19201
19202
19203
19204
19205
19206
19207
19208
19209
19210
19211
19212
19213
19214
19215
19216
19217
19218
19219
19220
19221
19222
19223
19224
19225
19226
19227
19228
19229
19230
19231
19232
19233
19234
19235
19236
19237
19238
19239
19240
19241
19242
19243
19244
19245
19246
19247
19248
19249
19250
19251
19252
19253
19254
19255
19256
19257
19258
19259
19260
19261
19262
19263
19264
19265
19266
19267
19268
19269
19270
19271
19272
19273
19274
19275
19276
19277
19278
19279
19280
19281
19282
19283
19284
19285
19286
19287
19288
19289
19290
19291
19292
19293
19294
19295
19296
19297
19298
19299
19300
19301
19302
19303
19304
19305
19306
19307
19308
19309
19310
19311
19312
19313
19314
19315
19316
19317
19318
19319
19320
19321
19322
19323
19324
19325
19326
19327
19328
19329
19330
19331
19332
19333
19334
19335
19336
19337
19338
19339
19340
19341
19342
19343
19344
19345
19346
19347
19348
19349
19350
19351
19352
19353
19354
19355
19356
19357
19358
19359
19360
19361
19362
19363
19364
19365
19366
19367
19368
19369
19370
19371
19372
19373
19374
19375
19376
19377
19378
19379
19380
19381
19382
19383
19384
19385
19386
19387
19388
19389
19390
19391
19392
19393
19394
19395
19396
19397
19398
19399
19400
19401
19402
19403
19404
19405
19406
19407
19408
19409
19410
19411
19412
19413
19414
19415
19416
19417
19418
19419
19420
19421
19422
19423
19424
19425
19426
19427
19428
19429
19430
19431
19432
19433
19434
19435
19436
19437
19438
19439
19440
19441
19442
19443
19444
19445
19446
19447
19448
19449
19450
19451
19452
19453
19454
19455
19456
19457
19458
19459
19460
19461
19462
19463
19464
19465
19466
19467
19468
19469
19470
19471
19472
19473
19474
19475
19476
19477
19478
19479
19480
19481
19482
19483
19484
19485
19486
19487
19488
19489
19490
19491
19492
19493
19494
19495
19496
19497
19498
19499
19500
19501
19502
19503
19504
19505
19506
19507
19508
19509
19510
19511
19512
19513
19514
19515
19516
19517
19518
19519
19520
19521
19522
19523
19524
19525
19526
19527
19528
19529
19530
19531
19532
19533
19534
19535
19536
19537
19538
19539
19540
19541
19542
19543
19544
19545
19546
19547
19548
19549
19550
19551
19552
19553
19554
19555
19556
19557
19558
19559
19560
19561
19562
19563
19564
19565
19566
19567
19568
19569
19570
19571
19572
19573
19574
19575
19576
19577
19578
19579
19580
19581
19582
19583
19584
19585
19586
19587
19588
19589
19590
19591
19592
19593
19594
19595
19596
19597
19598
19599
19600
19601
19602
19603
19604
19605
19606
19607
19608
19609
19610
19611
19612
19613
19614
19615
19616
19617
19618
19619
19620
19621
19622
19623
19624
19625
19626
19627
19628
19629
19630
19631
19632
19633
19634
19635
19636
19637
19638
19639
19640
19641
19642
19643
19644
19645
19646
19647
19648
19649
19650
19651
19652
19653
19654
19655
19656
19657
19658
19659
19660
19661
19662
19663
19664
19665
19666
19667
19668
19669
19670
19671
19672
19673
19674
19675
19676
19677
19678
19679
19680
19681
19682
19683
19684
19685
19686
19687
19688
19689
19690
19691
19692
19693
19694
19695
19696
19697
19698
19699
19700
19701
19702
19703
19704
19705
19706
19707
19708
19709
19710
19711
19712
19713
19714
19715
19716
19717
19718
19719
19720
19721
19722
19723
19724
19725
19726
19727
19728
19729
19730
19731
19732
19733
19734
19735
19736
19737
19738
19739
19740
19741
19742
19743
19744
19745
19746
19747
19748
19749
19750
19751
19752
19753
19754
19755
19756
19757
19758
19759
19760
19761
19762
19763
19764
19765
19766
19767
19768
19769
19770
19771
19772
19773
19774
19775
19776
19777
19778
19779
19780
19781
19782
19783
19784
19785
19786
19787
19788
19789
19790
19791
19792
19793
19794
19795
19796
19797
19798
19799 | <!doctype html public "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Postfix Configuration Parameters </title>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
</head>
<body>
<h1><img src="postfix-logo.jpg" width="203" height="98" alt="">Postfix Configuration Parameters </h1>
<hr>
<h2> Postfix main.cf file format </h2>
<p> The Postfix main.cf configuration file specifies a very small
subset of all the parameters that control the operation of the
Postfix mail system. Parameters not explicitly specified are left
at their default values. </p>
<p> The general format of the main.cf file is as follows: </p>
<ul>
<li> <p> Each logical line is in the form "parameter = value".
Whitespace around the "=" is ignored, as is whitespace at the end
of a logical line. </p>
<li> <p> Empty lines and whitespace-only lines are ignored, as are
lines whose first non-whitespace character is a `#'. </p>
<li> <p> A logical line starts with non-whitespace text. A line
that starts with whitespace continues a logical line. </p>
<li> <p> A parameter value may refer to other parameters. </p>
<ul>
<li> <p> The expressions "$name" and "${name}" are recursively
replaced with the value of the named parameter. The parameter name
must contain only characters from the set [a-zA-Z0-9_].
An undefined parameter value is replaced with the empty value. </p>
<li> <p> The expressions "${name?value}" and "${name?{value}}" are
replaced with "value" when "$name" is non-empty. The parameter name
must contain only characters from the set [a-zA-Z0-9_]. These forms are
supported with Postfix versions ≥ 2.2 and ≥ 3.0, respectively.
</p>
<li> <p> The expressions "${name:value}" and "${name:{value}}" are
replaced with "value" when "$name" is empty. The parameter name must
contain only characters from the set [a-zA-Z0-9_]. These forms are
supported with Postfix versions ≥ 2.2 and ≥ 3.0, respectively.
</p>
<li> <p> The expression "${name?{value1}:{value2}}" is replaced
with "value1" when "$name" is non-empty, and with "value2" when
"$name" is empty. The "{}" is required for "value1", optional for
"value2". The parameter name must contain only characters from the
set [a-zA-Z0-9_]. This form is supported with Postfix versions
≥ 3.0. </p>
<li> <p> The first item inside "${...}" may be a relational expression
of the form: "{value3} == {value4}". Besides the "==" (equality)
operator Postfix supports "!=" (inequality), "<", "≤", "≥",
and ">". The comparison is numerical when both operands are all
digits, otherwise the comparison is lexicographical. These forms
are supported with Postfix versions ≥ 3.0. </p>
<li> <p> Each "value" is subject to recursive named parameter and
relational expression evaluation, except where noted. </p>
<li> <p> Whitespace before or after each "{value}" is ignored. </p>
<li> <p> Specify "$$" to produce a single "$" character. </p>
<li> <p> The legacy form "$(...)" is equivalent to the preferred
form "${...}". </p>
</ul>
<li> <p> When the same parameter is defined multiple times, only
the last instance is remembered. </p>
<li> <p> Otherwise, the order of main.cf parameter definitions does
not matter. </p>
</ul>
<p> The remainder of this document is a description of all Postfix
configuration parameters. Default values are shown after the
parameter name in parentheses, and can be looked up with the
"<b>postconf -d</b>" command. </p>
<p> Note: this is not an invitation to make changes to Postfix
configuration parameters. Unnecessary changes are likely to impair
the operation of the mail system. </p>
<dl>
<DT><b><a name="2bounce_notice_recipient">2bounce_notice_recipient</a>
(default: postmaster)</b></DT><DD>
<p> The recipient of undeliverable mail that cannot be returned to
the sender. This feature is enabled with the <a href="postconf.5.html#notify_classes">notify_classes</a>
parameter. </p>
</DD>
<DT><b><a name="access_map_defer_code">access_map_defer_code</a>
(default: 450)</b></DT><DD>
<p>
The numerical Postfix SMTP server response code for
an <a href="access.5.html">access(5)</a> map "defer" action, including "<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>"
or "<a href="postconf.5.html#defer_if_reject">defer_if_reject</a>". Prior to Postfix 2.6, the response
is hard-coded as "450".
</p>
<p>
Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc5321">RFC 5321</a>.
</p>
<p>
This feature is available in Postfix 2.6 and later.
</p>
</DD>
<DT><b><a name="access_map_reject_code">access_map_reject_code</a>
(default: 554)</b></DT><DD>
<p>
The numerical Postfix SMTP server response code for
an <a href="access.5.html">access(5)</a> map "reject" action.
</p>
<p>
Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc5321">RFC 5321</a>.
</p>
</DD>
<DT><b><a name="address_verify_cache_cleanup_interval">address_verify_cache_cleanup_interval</a>
(default: 12h)</b></DT><DD>
<p> The amount of time between <a href="verify.8.html">verify(8)</a> address verification
database cleanup runs. This feature requires that the database
supports the "delete" and "sequence" operators. Specify a zero
interval to disable database cleanup. </p>
<p> After each database cleanup run, the <a href="verify.8.html">verify(8)</a> daemon logs the
number of entries that were retained and dropped. A cleanup run is
logged as "partial" when the daemon terminates early after "<b>postfix
reload</b>", "<b>postfix stop</b>", or no requests for $<a href="postconf.5.html#max_idle">max_idle</a>
seconds. </p>
<p> Time units: s (seconds), m (minutes), h (hours), d (days), w
(weeks). </p>
<p> This feature is available in Postfix 2.7. </p>
</DD>
<DT><b><a name="address_verify_default_transport">address_verify_default_transport</a>
(default: $<a href="postconf.5.html#default_transport">default_transport</a>)</b></DT><DD>
<p>
Overrides the <a href="postconf.5.html#default_transport">default_transport</a> parameter setting for address
verification probes.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="address_verify_local_transport">address_verify_local_transport</a>
(default: $<a href="postconf.5.html#local_transport">local_transport</a>)</b></DT><DD>
<p>
Overrides the <a href="postconf.5.html#local_transport">local_transport</a> parameter setting for address
verification probes.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="address_verify_map">address_verify_map</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
Lookup table for persistent address verification status
storage. The table is maintained by the <a href="verify.8.html">verify(8)</a> service, and
is opened before the process releases privileges.
</p>
<p>
The lookup table is persistent by default (Postfix 2.7 and later).
Specify an empty table name to keep the information in volatile
memory which is lost after "<b>postfix reload</b>" or "<b>postfix
stop</b>". This is the default with Postfix version 2.6 and earlier.
</p>
<p>
Specify a location in a file system that will not fill up. If the
database becomes corrupted, the world comes to an end. To recover
delete (NOT: truncate) the file and do "<b>postfix reload</b>".
</p>
<p> Postfix daemon processes do not use root privileges when opening
this file (Postfix 2.5 and later). The file must therefore be
stored under a Postfix-owned directory such as the <a href="postconf.5.html#data_directory">data_directory</a>.
As a migration aid, an attempt to open the file under a non-Postfix
directory is redirected to the Postfix-owned <a href="postconf.5.html#data_directory">data_directory</a>, and a
warning is logged. </p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#address_verify_map">address_verify_map</a> = <a href="DATABASE_README.html#types">hash</a>:/var/lib/postfix/verify
<a href="postconf.5.html#address_verify_map">address_verify_map</a> = <a href="DATABASE_README.html#types">btree</a>:/var/lib/postfix/verify
</pre>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="address_verify_negative_cache">address_verify_negative_cache</a>
(default: yes)</b></DT><DD>
<p>
Enable caching of failed address verification probe results. When
this feature is enabled, the cache may pollute quickly with garbage.
When this feature is disabled, Postfix will generate an address
probe for every lookup.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="address_verify_negative_expire_time">address_verify_negative_expire_time</a>
(default: 3d)</b></DT><DD>
<p>
The time after which a failed probe expires from the address
verification cache.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="address_verify_negative_refresh_time">address_verify_negative_refresh_time</a>
(default: 3h)</b></DT><DD>
<p>
The time after which a failed address verification probe needs to
be refreshed.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="address_verify_pending_request_limit">address_verify_pending_request_limit</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> A safety limit that prevents address verification requests from
overwhelming the Postfix queue. By default, the number of pending
requests is limited to 1/4 of the <a href="QSHAPE_README.html#active_queue">active queue</a> maximum size
(<a href="postconf.5.html#qmgr_message_active_limit">qmgr_message_active_limit</a>). The queue manager enforces the limit
by tempfailing requests that exceed the limit. This affects only
unknown addresses and inactive addresses that have expired, because
the <a href="verify.8.html">verify(8)</a> daemon automatically refreshes an active address
before it expires. </p>
<p> This feature is available in Postfix 3.1 and later. </p>
</DD>
<DT><b><a name="address_verify_poll_count">address_verify_poll_count</a>
(default: normal: 3, overload: 1)</b></DT><DD>
<p>
How many times to query the <a href="verify.8.html">verify(8)</a> service for the completion
of an address verification request in progress.
</p>
<p> By default, the Postfix SMTP server polls the <a href="verify.8.html">verify(8)</a> service
up to three times under non-overload conditions, and only once when
under overload. With Postfix version 2.5 and earlier, the SMTP
server always polls the <a href="verify.8.html">verify(8)</a> service up to three times by
default. </p>
<p>
Specify 1 to implement a crude form of greylisting, that is, always
defer the first delivery request for a new address.
</p>
<p>
Examples:
</p>
<pre>
# Postfix ≤ 2.6 default
<a href="postconf.5.html#address_verify_poll_count">address_verify_poll_count</a> = 3
# Poor man's greylisting
<a href="postconf.5.html#address_verify_poll_count">address_verify_poll_count</a> = 1
</pre>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="address_verify_poll_delay">address_verify_poll_delay</a>
(default: 3s)</b></DT><DD>
<p>
The delay between queries for the completion of an address
verification request in progress.
</p>
<p>
The default polling delay is 3 seconds.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="address_verify_positive_expire_time">address_verify_positive_expire_time</a>
(default: 31d)</b></DT><DD>
<p>
The time after which a successful probe expires from the address
verification cache.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="address_verify_positive_refresh_time">address_verify_positive_refresh_time</a>
(default: 7d)</b></DT><DD>
<p>
The time after which a successful address verification probe needs
to be refreshed. The address verification status is not updated
when the probe fails (optimistic caching).
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="address_verify_relay_transport">address_verify_relay_transport</a>
(default: $<a href="postconf.5.html#relay_transport">relay_transport</a>)</b></DT><DD>
<p>
Overrides the <a href="postconf.5.html#relay_transport">relay_transport</a> parameter setting for address
verification probes.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="address_verify_relayhost">address_verify_relayhost</a>
(default: $<a href="postconf.5.html#relayhost">relayhost</a>)</b></DT><DD>
<p>
Overrides the <a href="postconf.5.html#relayhost">relayhost</a> parameter setting for address verification
probes. This information can be overruled with the <a href="transport.5.html">transport(5)</a> table.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="address_verify_sender">address_verify_sender</a>
(default: $<a href="postconf.5.html#double_bounce_sender">double_bounce_sender</a>)</b></DT><DD>
<p> The sender address to use in address verification probes; prior
to Postfix 2.5 the default was "postmaster". To
avoid problems with address probes that are sent in response to
address probes, the Postfix SMTP server excludes the probe sender
address from all SMTPD access blocks. </p>
<p>
Specify an empty value (<a href="postconf.5.html#address_verify_sender">address_verify_sender</a> =) or <> if you want
to use the null sender address. Beware, some sites reject mail from
<>, even though RFCs require that such addresses be accepted.
</p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#address_verify_sender">address_verify_sender</a> = <>
<a href="postconf.5.html#address_verify_sender">address_verify_sender</a> = postmaster@my.domain
</pre>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="address_verify_sender_dependent_default_transport_maps">address_verify_sender_dependent_default_transport_maps</a>
(default: $<a href="postconf.5.html#sender_dependent_default_transport_maps">sender_dependent_default_transport_maps</a>)</b></DT><DD>
<p> Overrides the <a href="postconf.5.html#sender_dependent_default_transport_maps">sender_dependent_default_transport_maps</a> parameter
setting for address verification probes. </p>
<p> This feature is available in Postfix 2.7 and later. </p>
</DD>
<DT><b><a name="address_verify_sender_dependent_relayhost_maps">address_verify_sender_dependent_relayhost_maps</a>
(default: $<a href="postconf.5.html#sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a>)</b></DT><DD>
<p>
Overrides the <a href="postconf.5.html#sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a> parameter setting for address
verification probes.
</p>
<p>
This feature is available in Postfix 2.3 and later.
</p>
</DD>
<DT><b><a name="address_verify_sender_ttl">address_verify_sender_ttl</a>
(default: 0s)</b></DT><DD>
<p> The time between changes in the time-dependent portion of address
verification probe sender addresses. The time-dependent portion is
appended to the localpart of the address specified with the
<a href="postconf.5.html#address_verify_sender">address_verify_sender</a> parameter. This feature is ignored when the
probe sender addresses is the null sender, i.e. the <a href="postconf.5.html#address_verify_sender">address_verify_sender</a>
value is empty or <>. </p>
<p> Historically, the probe sender address was fixed. This has
caused such addresses to end up on spammer mailing lists, and has
resulted in wasted network and processing resources. </p>
<p> To enable time-dependent probe sender addresses, specify a
non-zero time value (an integral value plus an optional one-letter
suffix that specifies the time unit). Specify a value of at least
several hours, to avoid problems with senders that use greylisting.
Avoid nice TTL values, to make the result less predictable. Time
units are: s (seconds), m (minutes), h (hours), d (days), w (weeks).
</p>
<p> This feature is available in Postfix 2.9 and later. </p>
</DD>
<DT><b><a name="address_verify_service_name">address_verify_service_name</a>
(default: verify)</b></DT><DD>
<p>
The name of the <a href="verify.8.html">verify(8)</a> address verification service. This service
maintains the status of sender and/or recipient address verification
probes, and generates probes on request by other Postfix processes.
</p>
</DD>
<DT><b><a name="address_verify_transport_maps">address_verify_transport_maps</a>
(default: $<a href="postconf.5.html#transport_maps">transport_maps</a>)</b></DT><DD>
<p>
Overrides the <a href="postconf.5.html#transport_maps">transport_maps</a> parameter setting for address verification
probes.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="address_verify_virtual_transport">address_verify_virtual_transport</a>
(default: $<a href="postconf.5.html#virtual_transport">virtual_transport</a>)</b></DT><DD>
<p>
Overrides the <a href="postconf.5.html#virtual_transport">virtual_transport</a> parameter setting for address
verification probes.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="alias_database">alias_database</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
The alias databases for <a href="local.8.html">local(8)</a> delivery that are updated with
"<b>newaliases</b>" or with "<b>sendmail -bi</b>".
</p>
<p>
This is a separate configuration parameter because not all the
tables specified with $<a href="postconf.5.html#alias_maps">alias_maps</a> have to be local files.
</p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#alias_database">alias_database</a> = <a href="DATABASE_README.html#types">hash</a>:/etc/aliases
<a href="postconf.5.html#alias_database">alias_database</a> = <a href="DATABASE_README.html#types">hash</a>:/etc/mail/aliases
</pre>
</DD>
<DT><b><a name="alias_maps">alias_maps</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
The alias databases that are used for <a href="local.8.html">local(8)</a> delivery. See
<a href="aliases.5.html">aliases(5)</a> for syntax details.
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found.
Note: these lookups are recursive.
</p>
<p>
The default list is system dependent. On systems with NIS, the
default is to search the local alias database, then the NIS alias
database.
</p>
<p>
If you change the alias database, run "<b>postalias /etc/aliases</b>"
(or wherever your system stores the mail alias file), or simply
run "<b>newaliases</b>" to build the necessary DBM or DB file.
</p>
<p>
The <a href="local.8.html">local(8)</a> delivery agent disallows regular expression substitution
of $1 etc. in <a href="postconf.5.html#alias_maps">alias_maps</a>, because that would open a security hole.
</p>
<p>
The <a href="local.8.html">local(8)</a> delivery agent will silently ignore requests to use
the <a href="proxymap.8.html">proxymap(8)</a> server within <a href="postconf.5.html#alias_maps">alias_maps</a>. Instead it will open the
table directly. Before Postfix version 2.2, the <a href="local.8.html">local(8)</a> delivery
agent will terminate with a fatal error.
</p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#alias_maps">alias_maps</a> = <a href="DATABASE_README.html#types">hash</a>:/etc/aliases, nis:mail.aliases
<a href="postconf.5.html#alias_maps">alias_maps</a> = <a href="DATABASE_README.html#types">hash</a>:/etc/aliases
</pre>
</DD>
<DT><b><a name="allow_mail_to_commands">allow_mail_to_commands</a>
(default: alias, forward)</b></DT><DD>
<p>
Restrict <a href="local.8.html">local(8)</a> mail delivery to external commands. The default
is to disallow delivery to "|command" in :include: files (see
<a href="aliases.5.html">aliases(5)</a> for the text that defines this terminology).
</p>
<p>
Specify zero or more of: <b>alias</b>, <b>forward</b> or <b>include</b>,
in order to allow commands in <a href="aliases.5.html">aliases(5)</a>, .forward files or in
:include: files, respectively.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#allow_mail_to_commands">allow_mail_to_commands</a> = alias,forward,include
</pre>
</DD>
<DT><b><a name="allow_mail_to_files">allow_mail_to_files</a>
(default: alias, forward)</b></DT><DD>
<p>
Restrict <a href="local.8.html">local(8)</a> mail delivery to external files. The default is
to disallow "/file/name" destinations in :include: files (see
<a href="aliases.5.html">aliases(5)</a> for the text that defines this terminology).
</p>
<p>
Specify zero or more of: <b>alias</b>, <b>forward</b> or <b>include</b>,
in order to allow "/file/name" destinations in <a href="aliases.5.html">aliases(5)</a>, .forward
files and in :include: files, respectively.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#allow_mail_to_files">allow_mail_to_files</a> = alias,forward,include
</pre>
</DD>
<DT><b><a name="allow_min_user">allow_min_user</a>
(default: no)</b></DT><DD>
<p>
Allow a sender or recipient address to have `-' as the first
character. By
default, this is not allowed, to avoid accidents with software that
passes email addresses via the command line. Such software
would not be able to distinguish a malicious address from a
bona fide command-line option. Although this can be prevented by
inserting a "--" option terminator into the command line, this is
difficult to enforce consistently and globally. </p>
<p> As of Postfix version 2.5, this feature is implemented by
<a href="trivial-rewrite.8.html">trivial-rewrite(8)</a>. With earlier versions this feature was implemented
by <a href="qmgr.8.html">qmgr(8)</a> and was limited to recipient addresses only. </p>
</DD>
<DT><b><a name="allow_percent_hack">allow_percent_hack</a>
(default: yes)</b></DT><DD>
<p>
Enable the rewriting of the form "user%domain" to "user@domain".
This is enabled by default.
</p>
<p> Note: as of Postfix version 2.2, message header address rewriting
happens only when one of the following conditions is true: </p>
<ul>
<li> The message is received with the Postfix <a href="sendmail.1.html">sendmail(1)</a> command,
<li> The message is received from a network client that matches
$<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a>,
<li> The message is received from the network, and the
<a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> parameter specifies a non-empty value.
</ul>
<p> To get the behavior before Postfix version 2.2, specify
"<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = <a href="DATABASE_README.html#types">static</a>:all". </p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#allow_percent_hack">allow_percent_hack</a> = no
</pre>
</DD>
<DT><b><a name="allow_untrusted_routing">allow_untrusted_routing</a>
(default: no)</b></DT><DD>
<p>
Forward mail with sender-specified routing (user[@%!]remote[@%!]site)
from untrusted clients to destinations matching $<a href="postconf.5.html#relay_domains">relay_domains</a>.
</p>
<p>
By default, this feature is turned off. This closes a nasty open
relay loophole where a backup MX host can be tricked into forwarding
junk mail to a primary MX host which then spams it out to the world.
</p>
<p>
This parameter also controls if non-local addresses with sender-specified
routing can match Postfix access tables. By default, such addresses
cannot match Postfix access tables, because the address is ambiguous.
</p>
</DD>
<DT><b><a name="alternate_config_directories">alternate_config_directories</a>
(default: empty)</b></DT><DD>
<p>
A list of non-default Postfix configuration directories that may
be specified with "-c <a href="postconf.5.html#config_directory">config_directory</a>" on the command line (in the
case of <a href="sendmail.1.html">sendmail(1)</a>, with the "-C" option), or via the MAIL_CONFIG
environment parameter.
</p>
<p>
This list must be specified in the default Postfix <a href="postconf.5.html">main.cf</a> file,
and will be used by set-gid Postfix commands such as <a href="postqueue.1.html">postqueue(1)</a>
and <a href="postdrop.1.html">postdrop(1)</a>.
</p>
<p>
Specify absolute pathnames, separated by comma or space. Note: $name
expansion is not supported.
</p>
</DD>
<DT><b><a name="always_add_missing_headers">always_add_missing_headers</a>
(default: no)</b></DT><DD>
<p> Always add (Resent-) From:, To:, Date: or Message-ID: headers
when not present. Postfix 2.6 and later add these headers only
when clients match the <a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> parameter
setting. Earlier Postfix versions always add these headers; this
may break DKIM signatures that cover non-existent headers.
The <a href="postconf.5.html#undisclosed_recipients_header">undisclosed_recipients_header</a> parameter setting determines
whether a To: header will be added. </p>
</DD>
<DT><b><a name="always_bcc">always_bcc</a>
(default: empty)</b></DT><DD>
<p>
Optional address that receives a "blind carbon copy" of each message
that is received by the Postfix mail system.
</p>
<p>
Note: with Postfix 2.3 and later the BCC address is added as if it
was specified with NOTIFY=NONE. The sender will not be notified
when the BCC address is undeliverable, as long as all down-stream
software implements <a href="http://tools.ietf.org/html/rfc3461">RFC 3461</a>.
</p>
<p>
Note: with Postfix 2.2 and earlier the sender will be notified
when the BCC address is undeliverable.
</p>
<p> Note: automatic BCC recipients are produced only for new mail.
To avoid mailer loops, automatic BCC recipients are not generated
after Postfix forwards mail internally, or after Postfix generates
mail itself. </p>
</DD>
<DT><b><a name="anvil_rate_time_unit">anvil_rate_time_unit</a>
(default: 60s)</b></DT><DD>
<p>
The time unit over which client connection rates and other rates
are calculated.
</p>
<p>
This feature is implemented by the <a href="anvil.8.html">anvil(8)</a> service which is available
in Postfix version 2.2 and later.
</p>
<p>
The default interval is relatively short. Because of the high
frequency of updates, the <a href="anvil.8.html">anvil(8)</a> server uses volatile memory
only. Thus, information is lost whenever the process terminates.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="anvil_status_update_time">anvil_status_update_time</a>
(default: 600s)</b></DT><DD>
<p>
How frequently the <a href="anvil.8.html">anvil(8)</a> connection and rate limiting server
logs peak usage information.
</p>
<p>
This feature is available in Postfix 2.2 and later.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="append_at_myorigin">append_at_myorigin</a>
(default: yes)</b></DT><DD>
<p>
With locally submitted mail, append the string "@$<a href="postconf.5.html#myorigin">myorigin</a>" to mail
addresses without domain information. With remotely submitted mail,
append the string "@$<a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a>" instead.
</p>
<p>
Note 1: this feature is enabled by default and must not be turned off.
Postfix does not support domain-less addresses.
</p>
<p> Note 2: with Postfix version 2.2, message header address rewriting
happens only when one of the following conditions is true: </p>
<ul>
<li> The message is received with the Postfix <a href="sendmail.1.html">sendmail(1)</a> command,
<li> The message is received from a network client that matches
$<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a>,
<li> The message is received from the network, and the
<a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> parameter specifies a non-empty value.
</ul>
<p> To get the behavior before Postfix version 2.2, specify
"<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = <a href="DATABASE_README.html#types">static</a>:all". </p>
</DD>
<DT><b><a name="append_dot_mydomain">append_dot_mydomain</a>
(default: Postfix ≥ 3.0: no, Postfix < 3.0: yes)</b></DT><DD>
<p>
With locally submitted mail, append the string ".$<a href="postconf.5.html#mydomain">mydomain</a>" to
addresses that have no ".domain" information. With remotely submitted
mail, append the string ".$<a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a>"
instead.
</p>
<p>
Note 1: this feature is enabled by default. If disabled, users will not be
able to send mail to "user@partialdomainname" but will have to
specify full domain names instead.
</p>
<p> Note 2: with Postfix version 2.2, message header address rewriting
happens only when one of the following conditions is true: </p>
<ul>
<li> The message is received with the Postfix <a href="sendmail.1.html">sendmail(1)</a> command,
<li> The message is received from a network client that matches
$<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a>,
<li> The message is received from the network, and the
<a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> parameter specifies a non-empty value.
</ul>
<p> To get the behavior before Postfix version 2.2, specify
"<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = <a href="DATABASE_README.html#types">static</a>:all". </p>
</DD>
<DT><b><a name="application_event_drain_time">application_event_drain_time</a>
(default: 100s)</b></DT><DD>
<p>
How long the <a href="postkick.1.html">postkick(1)</a> command waits for a request to enter the
Postfix daemon process input buffer before giving up.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="authorized_flush_users">authorized_flush_users</a>
(default: <a href="DATABASE_README.html#types">static</a>:anyone)</b></DT><DD>
<p>
List of users who are authorized to flush the queue.
</p>
<p>
By default, all users are allowed to flush the queue. Access is
always granted if the invoking user is the super-user or the
$<a href="postconf.5.html#mail_owner">mail_owner</a> user. Otherwise, the real UID of the process is looked
up in the system password file, and access is granted only if the
corresponding login name is on the access list. The username
"unknown" is used for processes whose real UID is not found in the
password file. </p>
<p>
Specify a list of user names, "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns,
separated by commas and/or whitespace. The list is matched left to
right, and the search stops on the first match. A "/file/name"
pattern is replaced
by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table is matched when a name
matches a lookup key (the lookup result is ignored). Continue long
lines by starting the next line with whitespace. Specify "!pattern"
to exclude a name from the list. The form "!/file/name" is supported
only in Postfix version 2.4 and later. </p>
<p>
This feature is available in Postfix 2.2 and later.
</p>
</DD>
<DT><b><a name="authorized_mailq_users">authorized_mailq_users</a>
(default: <a href="DATABASE_README.html#types">static</a>:anyone)</b></DT><DD>
<p>
List of users who are authorized to view the queue.
</p>
<p>
By default, all users are allowed to view the queue. Access is
always granted if the invoking user is the super-user or the
$<a href="postconf.5.html#mail_owner">mail_owner</a> user. Otherwise, the real UID of the process is looked
up in the system password file, and access is granted only if the
corresponding login name is on the access list. The username
"unknown" is used for processes whose real UID is not found in the
password file. </p>
<p>
Specify a list of user names, "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns,
separated by commas and/or whitespace. The list is matched left to
right, and the search stops on the first match. A "/file/name"
pattern is replaced
by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table is matched when a name
matches a lookup key (the lookup result is ignored). Continue long
lines by starting the next line with whitespace. Specify "!pattern"
to exclude a user name from the list. The form "!/file/name" is
supported only in Postfix version 2.4 and later. </p>
<p>
This feature is available in Postfix 2.2 and later.
</p>
</DD>
<DT><b><a name="authorized_submit_users">authorized_submit_users</a>
(default: <a href="DATABASE_README.html#types">static</a>:anyone)</b></DT><DD>
<p>
List of users who are authorized to submit mail with the <a href="sendmail.1.html">sendmail(1)</a>
command (and with the privileged <a href="postdrop.1.html">postdrop(1)</a> helper command).
</p>
<p>
By default, all users are allowed to submit mail. Otherwise, the
real UID of the process is looked up in the system password file,
and access is granted only if the corresponding login name is on
the access list. The username "unknown" is used for processes
whose real UID is not found in the password file. To deny mail
submission access to all users specify an empty list. </p>
<p>
Specify a list of user names, "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns,
separated by commas and/or whitespace. The list is matched left to right,
and the search stops on the first match. A "/file/name" pattern is
replaced by its contents;
a "<a href="DATABASE_README.html">type:table</a>" lookup table is matched when a name matches a lookup key
(the lookup result is ignored). Continue long lines by starting the
next line with whitespace. Specify "!pattern" to exclude a user
name from the list. The form "!/file/name" is supported only in
Postfix version 2.4 and later. </p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#authorized_submit_users">authorized_submit_users</a> = !www, <a href="DATABASE_README.html#types">static</a>:all
</pre>
<p>
This feature is available in Postfix 2.2 and later.
</p>
</DD>
<DT><b><a name="authorized_verp_clients">authorized_verp_clients</a>
(default: $<a href="postconf.5.html#mynetworks">mynetworks</a>)</b></DT><DD>
<p> What remote SMTP clients are allowed to specify the XVERP command.
This command requests that mail be delivered one recipient at a
time with a per recipient return address. </p>
<p> By default, only trusted clients are allowed to specify XVERP.
</p>
<p> This parameter was introduced with Postfix version 1.1. Postfix
version 2.1 renamed this parameter to <a href="postconf.5.html#smtpd_authorized_verp_clients">smtpd_authorized_verp_clients</a>
and changed the default to none. </p>
<p> Specify a list of network/netmask patterns, separated by commas
and/or whitespace. The mask specifies the number of bits in the
network part of a host address. You can also specify hostnames or
.domain names (the initial dot causes the domain to match any name
below it), "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns. A "/file/name"
pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table
is matched when a table entry matches a lookup string (the lookup
result is ignored). Continue long lines by starting the next line
with whitespace. Specify "!pattern" to exclude an address or network
block from the list. The form "!/file/name" is supported only in
Postfix version 2.4 and later. </p>
<p> Note: IP version 6 address information must be specified inside
<tt>[]</tt> in the <a href="postconf.5.html#authorized_verp_clients">authorized_verp_clients</a> value, and in files
specified with "/file/name". IP version 6 addresses contain the
":" character, and would otherwise be confused with a "<a href="DATABASE_README.html">type:table</a>"
pattern. </p>
</DD>
<DT><b><a name="backwards_bounce_logfile_compatibility">backwards_bounce_logfile_compatibility</a>
(default: yes)</b></DT><DD>
<p>
Produce additional <a href="bounce.8.html">bounce(8)</a> logfile records that can be read by
Postfix versions before 2.0. The current and more extensible "name =
value" format is needed in order to implement more sophisticated
functionality.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="berkeley_db_create_buffer_size">berkeley_db_create_buffer_size</a>
(default: 16777216)</b></DT><DD>
<p>
The per-table I/O buffer size for programs that create Berkeley DB
hash or btree tables. Specify a byte count.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="berkeley_db_read_buffer_size">berkeley_db_read_buffer_size</a>
(default: 131072)</b></DT><DD>
<p>
The per-table I/O buffer size for programs that read Berkeley DB
hash or btree tables. Specify a byte count.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="best_mx_transport">best_mx_transport</a>
(default: empty)</b></DT><DD>
<p>
Where the Postfix SMTP client should deliver mail when it detects
a "mail loops back to myself" error condition. This happens when
the local MTA is the best SMTP mail exchanger for a destination
not listed in $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>, $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>,
$<a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a>, or $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>. By default,
the Postfix SMTP client returns such mail as undeliverable.
</p>
<p>
Specify, for example, "<a href="postconf.5.html#best_mx_transport">best_mx_transport</a> = local" to pass the mail
from the Postfix SMTP client to the <a href="local.8.html">local(8)</a> delivery agent. You
can specify
any message delivery "transport" or "transport:nexthop" that is
defined in the <a href="master.5.html">master.cf</a> file. See the <a href="transport.5.html">transport(5)</a> manual page
for the syntax and meaning of "transport" or "transport:nexthop".
</p>
<p>
However, this feature is expensive because it ties up a Postfix
SMTP client process while the <a href="local.8.html">local(8)</a> delivery agent is doing its
work. It is more efficient (for Postfix) to list all <a href="VIRTUAL_README.html#canonical">hosted domains</a>
in a table or database.
</p>
</DD>
<DT><b><a name="biff">biff</a>
(default: yes)</b></DT><DD>
<p>
Whether or not to use the local <a href="postconf.5.html#biff">biff</a> service. This service sends
"new mail" notifications to users who have requested new mail
notification with the UNIX command "<a href="postconf.5.html#biff">biff</a> y".
</p>
<p>
For compatibility reasons this feature is on by default. On systems
with lots of interactive users, the <a href="postconf.5.html#biff">biff</a> service can be a performance
drain. Specify "<a href="postconf.5.html#biff">biff</a> = no" in <a href="postconf.5.html">main.cf</a> to disable.
</p>
</DD>
<DT><b><a name="body_checks">body_checks</a>
(default: empty)</b></DT><DD>
<p> Optional lookup tables for content inspection as specified in
the <a href="header_checks.5.html">body_checks(5)</a> manual page. </p>
<p> Note: with Postfix versions before 2.0, these rules inspect
all content after the primary message headers. </p>
</DD>
<DT><b><a name="body_checks_size_limit">body_checks_size_limit</a>
(default: 51200)</b></DT><DD>
<p>
How much text in a message body segment (or attachment, if you
prefer to use that term) is subjected to <a href="postconf.5.html#body_checks">body_checks</a> inspection.
The amount of text is limited to avoid scanning huge attachments.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="bounce_notice_recipient">bounce_notice_recipient</a>
(default: postmaster)</b></DT><DD>
<p>
The recipient of postmaster notifications with the message headers
of mail that Postfix did not deliver and of SMTP conversation
transcripts of mail that Postfix did not receive. This feature is
enabled with the <a href="postconf.5.html#notify_classes">notify_classes</a> parameter. </p>
</DD>
<DT><b><a name="bounce_queue_lifetime">bounce_queue_lifetime</a>
(default: 5d)</b></DT><DD>
<p>
Consider a bounce message as undeliverable, when delivery fails
with a temporary error, and the time in the queue has reached the
<a href="postconf.5.html#bounce_queue_lifetime">bounce_queue_lifetime</a> limit. By default, this limit is the same
as for regular mail.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is d (days).
</p>
<p>
Specify 0 when mail delivery should be tried only once.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="bounce_service_name">bounce_service_name</a>
(default: bounce)</b></DT><DD>
<p>
The name of the <a href="bounce.8.html">bounce(8)</a> service. This service maintains a record
of failed delivery attempts and generates non-delivery notifications.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="bounce_size_limit">bounce_size_limit</a>
(default: 50000)</b></DT><DD>
<p> The maximal amount of original message text that is sent in a
non-delivery notification. Specify a byte count. A message is
returned as either message/rfc822 (the complete original) or as
text/rfc822-headers (the headers only). With Postfix version 2.4
and earlier, a message is always returned as message/rfc822 and is
truncated when it exceeds the size limit.
</p>
<p> Notes: </p>
<ul>
<li> <p> If you increase this limit, then you should increase the
<a href="postconf.5.html#mime_nesting_limit">mime_nesting_limit</a> value proportionally. </p>
<li> <p> Be careful when making changes. Excessively large values
will result in the loss of non-delivery notifications, when a bounce
message size exceeds a local or remote MTA's message size limit.
</p>
</ul>
</DD>
<DT><b><a name="bounce_template_file">bounce_template_file</a>
(default: empty)</b></DT><DD>
<p> Pathname of a configuration file with bounce message templates.
These override the built-in templates of delivery status notification
(DSN) messages for undeliverable mail, for delayed mail, successful
delivery, or delivery verification. The <a href="bounce.5.html">bounce(5)</a> manual page
describes how to edit and test template files. </p>
<p> Template message body text may contain $name references to
Postfix configuration parameters. The result of $name expansion can
be previewed with "<b>postconf -b <i>file_name</i></b>" before the file
is placed into the Postfix configuration directory. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="broken_sasl_auth_clients">broken_sasl_auth_clients</a>
(default: no)</b></DT><DD>
<p>
Enable interoperability with remote SMTP clients that implement an obsolete
version of the AUTH command (<a href="http://tools.ietf.org/html/rfc4954">RFC 4954</a>). Examples of such clients
are MicroSoft Outlook Express version 4 and MicroSoft Exchange
version 5.0.
</p>
<p>
Specify "<a href="postconf.5.html#broken_sasl_auth_clients">broken_sasl_auth_clients</a> = yes" to have Postfix advertise
AUTH support in a non-standard way.
</p>
</DD>
<DT><b><a name="canonical_classes">canonical_classes</a>
(default: envelope_sender, envelope_recipient, header_sender, header_recipient)</b></DT><DD>
<p> What addresses are subject to <a href="postconf.5.html#canonical_maps">canonical_maps</a> address mapping.
By default, <a href="postconf.5.html#canonical_maps">canonical_maps</a> address mapping is applied to envelope
sender and recipient addresses, and to header sender and header
recipient addresses. </p>
<p> Specify one or more of: envelope_sender, envelope_recipient,
header_sender, header_recipient </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="canonical_maps">canonical_maps</a>
(default: empty)</b></DT><DD>
<p>
Optional address mapping lookup tables for message headers and
envelopes. The mapping is applied to both sender and recipient
addresses, in both envelopes and in headers, as controlled
with the <a href="postconf.5.html#canonical_classes">canonical_classes</a> parameter. This is typically used
to clean up dirty addresses from legacy mail systems, or to replace
login names by Firstname.Lastname. The table format and lookups
are documented in <a href="canonical.5.html">canonical(5)</a>. For an overview of Postfix address
manipulations see the <a href="ADDRESS_REWRITING_README.html">ADDRESS_REWRITING_README</a> document.
</p>
<p>
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found.
Note: these lookups are recursive.
</p>
<p>
If you use this feature, run "<b>postmap /etc/postfix/canonical</b>" to
build the necessary DBM or DB file after every change. The changes
will become visible after a minute or so. Use "<b>postfix reload</b>"
to eliminate the delay.
</p>
<p> Note: with Postfix version 2.2, message header address mapping
happens only when message header address rewriting is enabled: </p>
<ul>
<li> The message is received with the Postfix <a href="sendmail.1.html">sendmail(1)</a> command,
<li> The message is received from a network client that matches
$<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a>,
<li> The message is received from the network, and the
<a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> parameter specifies a non-empty value.
</ul>
<p> To get the behavior before Postfix version 2.2, specify
"<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = <a href="DATABASE_README.html#types">static</a>:all". </p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#canonical_maps">canonical_maps</a> = <a href="DATABASE_README.html#types">dbm</a>:/etc/postfix/canonical
<a href="postconf.5.html#canonical_maps">canonical_maps</a> = <a href="DATABASE_README.html#types">hash</a>:/etc/postfix/canonical
</pre>
</DD>
<DT><b><a name="cleanup_service_name">cleanup_service_name</a>
(default: cleanup)</b></DT><DD>
<p>
The name of the <a href="cleanup.8.html">cleanup(8)</a> service. This service rewrites addresses
into the standard form, and performs <a href="canonical.5.html">canonical(5)</a> address mapping
and <a href="virtual.5.html">virtual(5)</a> aliasing.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="command_directory">command_directory</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
The location of all postfix administrative commands.
</p>
</DD>
<DT><b><a name="command_execution_directory">command_execution_directory</a>
(default: empty)</b></DT><DD>
<p> The <a href="local.8.html">local(8)</a> delivery agent working directory for delivery to
external command. Failure to change directory causes the delivery
to be deferred. </p>
<p> The following $name expansions are done on <a href="postconf.5.html#command_execution_directory">command_execution_directory</a>
before the directory is changed. Expansion happens in the context
of the delivery request. The result of $name expansion is filtered
with the character set that is specified with the
<a href="postconf.5.html#execution_directory_expansion_filter">execution_directory_expansion_filter</a> parameter. </p>
<dl>
<dt><b>$user</b></dt>
<dd>The recipient's username. </dd>
<dt><b>$shell</b></dt>
<dd>The recipient's login shell pathname. </dd>
<dt><b>$home</b></dt>
<dd>The recipient's home directory. </dd>
<dt><b>$recipient</b></dt>
<dd>The full recipient address. </dd>
<dt><b>$extension</b></dt>
<dd>The optional recipient address extension. </dd>
<dt><b>$domain</b></dt>
<dd>The recipient domain. </dd>
<dt><b>$local</b></dt>
<dd>The entire recipient localpart. </dd>
<dt><b>$<a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a></b></dt>
<dd>The address extension delimiter that was found in the recipient
address (Postfix 2.11 and later), or the system-wide recipient
address extension delimiter (Postfix 2.10 and earlier). </dd>
<dt><b>${name?value}</b></dt>
<dd>Expands to <i>value</i> when <i>$name</i> is non-empty. </dd>
<dt><b>${name:value}</b></dt>
<dd>Expands to <i>value</i> when <i>$name</i> is empty. </dd>
</dl>
<p>
Instead of $name you can also specify ${name} or $(name).
</p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="command_expansion_filter">command_expansion_filter</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
Restrict the characters that the <a href="local.8.html">local(8)</a> delivery agent allows in
$name expansions of $<a href="postconf.5.html#mailbox_command">mailbox_command</a> and $<a href="postconf.5.html#command_execution_directory">command_execution_directory</a>.
Characters outside the
allowed set are replaced by underscores.
</p>
</DD>
<DT><b><a name="command_time_limit">command_time_limit</a>
(default: 1000s)</b></DT><DD>
<p>
Time limit for delivery to external commands. This limit is used
by the <a href="local.8.html">local(8)</a> delivery agent, and is the default time limit for
delivery by the <a href="pipe.8.html">pipe(8)</a> delivery agent.
</p>
<p>
Note: if you set this time limit to a large value you must update the
global <a href="postconf.5.html#ipc_timeout">ipc_timeout</a> parameter as well.
</p>
</DD>
<DT><b><a name="compatibility_level">compatibility_level</a>
(default: 0)</b></DT><DD>
<p> A safety net that causes Postfix to run with backwards-compatible
default settings after an upgrade to a newer Postfix version. </p>
<p> With backwards compatibility turned on (the <a href="postconf.5.html">main.cf</a> <a href="postconf.5.html#compatibility_level">compatibility_level</a>
value is less than the Postfix built-in value), Postfix looks for
settings that are left at their implicit default value, and logs a
message when a backwards-compatible default setting is required.
</p>
<blockquote>
<pre>
using backwards-compatible default setting <i>name=value</i>
to [accept a specific client request]
using backwards-compatible default setting <i>name=value</i>
to [enable specific Postfix behavior]
</pre>
</blockquote>
<p> See <a href="COMPATIBILITY_README.html">COMPATIBILITY_README</a> for specific message details. If such
a message is logged in the context of a legitimate request, the
system administrator should make the backwards-compatible setting
permanent in <a href="postconf.5.html">main.cf</a> or <a href="master.5.html">master.cf</a>, for example: </p>
<blockquote>
<pre>
# <b>postconf</b> <i>name=value</i>
# <b>postfix reload</b>
</pre>
</blockquote>
<p> When no more backwards-compatible settings need to be made
permanent, the administrator should turn off backwards compatibility
by updating the <a href="postconf.5.html#compatibility_level">compatibility_level</a> setting in <a href="postconf.5.html">main.cf</a>:</p>
<blockquote>
<pre>
# <b>postconf <a href="postconf.5.html#compatibility_level">compatibility_level</a>=<i>N</i></b>
# <b>postfix reload</b>
</pre>
</blockquote>
<p> For <i>N</i> specify the number that is logged in your <a href="postfix.1.html">postfix(1)</a>
warning message: </p>
<blockquote>
<pre>
warning: To disable backwards compatibility use "postconf
<a href="postconf.5.html#compatibility_level">compatibility_level</a>=<i>N</i>" and "postfix reload"
</pre>
</blockquote>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="config_directory">config_directory</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> The default location of the Postfix <a href="postconf.5.html">main.cf</a> and <a href="master.5.html">master.cf</a>
configuration files. This can be overruled via the following
mechanisms: </p>
<ul>
<li> <p> The MAIL_CONFIG environment variable (daemon processes
and commands). </p>
<li> <p> The "-c" command-line option (commands only). </p>
</ul>
<p> With Postfix command that run with set-gid privileges, a
<a href="postconf.5.html#config_directory">config_directory</a> override requires either root privileges, or it
requires that the directory is listed with the <a href="postconf.5.html#alternate_config_directories">alternate_config_directories</a>
parameter in the default <a href="postconf.5.html">main.cf</a> file. </p>
</DD>
<DT><b><a name="confirm_delay_cleared">confirm_delay_cleared</a>
(default: no)</b></DT><DD>
<p> After sending a "your message is delayed" notification, inform
the sender when the delay clears up. This can result in a sudden
burst of notifications at the end of a prolonged network outage,
and is therefore disabled by default. </p>
<p> See also: <a href="postconf.5.html#delay_warning_time">delay_warning_time</a>. </p>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="connection_cache_protocol_timeout">connection_cache_protocol_timeout</a>
(default: 5s)</b></DT><DD>
<p> Time limit for connection cache connect, send or receive
operations. The time limit is enforced in the client. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="connection_cache_service_name">connection_cache_service_name</a>
(default: scache)</b></DT><DD>
<p> The name of the <a href="scache.8.html">scache(8)</a> connection cache service. This service
maintains a limited pool of cached sessions. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="connection_cache_status_update_time">connection_cache_status_update_time</a>
(default: 600s)</b></DT><DD>
<p> How frequently the <a href="scache.8.html">scache(8)</a> server logs usage statistics with
connection cache hit and miss rates for logical destinations and for
physical endpoints. </p>
</DD>
<DT><b><a name="connection_cache_ttl_limit">connection_cache_ttl_limit</a>
(default: 2s)</b></DT><DD>
<p> The maximal time-to-live value that the <a href="scache.8.html">scache(8)</a> connection
cache server
allows. Requests that specify a larger TTL will be stored with the
maximum allowed TTL. The purpose of this additional control is to
protect the infrastructure against careless people. The cache TTL
is already bounded by $<a href="postconf.5.html#max_idle">max_idle</a>. </p>
</DD>
<DT><b><a name="content_filter">content_filter</a>
(default: empty)</b></DT><DD>
<p> After the message is queued, send the entire message to the
specified <i>transport:destination</i>. The <i>transport</i> name
specifies the first field of a mail delivery agent definition in
<a href="master.5.html">master.cf</a>; the syntax of the next-hop <i>destination</i> is described
in the manual page of the corresponding delivery agent. More
information about external content filters is in the Postfix
<a href="FILTER_README.html">FILTER_README</a> file. </p>
<p> Notes: </p>
<ul>
<li> <p> This setting has lower precedence than a FILTER action
that is specified in an <a href="access.5.html">access(5)</a>, <a href="header_checks.5.html">header_checks(5)</a> or <a href="header_checks.5.html">body_checks(5)</a>
table. </p>
<li> <p> The meaning of an empty next-hop filter <i>destination</i>
is version dependent. Postfix 2.7 and later will use the recipient
domain; earlier versions will use $<a href="postconf.5.html#myhostname">myhostname</a>. Specify
"<a href="postconf.5.html#default_filter_nexthop">default_filter_nexthop</a> = $<a href="postconf.5.html#myhostname">myhostname</a>" for compatibility with Postfix
2.6 or earlier, or specify a <a href="postconf.5.html#content_filter">content_filter</a> value with an explicit
next-hop <i>destination</i>. </p>
</ul>
</DD>
<DT><b><a name="cyrus_sasl_config_path">cyrus_sasl_config_path</a>
(default: empty)</b></DT><DD>
<p> Search path for Cyrus SASL application configuration files,
currently used only to locate the $<a href="postconf.5.html#smtpd_sasl_path">smtpd_sasl_path</a>.conf file.
Specify zero or more directories separated by a colon character,
or an empty value to use Cyrus SASL's built-in search path. </p>
<p> This feature is available in Postfix 2.5 and later when compiled
with Cyrus SASL 2.1.22 or later. </p>
</DD>
<DT><b><a name="daemon_directory">daemon_directory</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
The directory with Postfix support programs and daemon programs.
These should not be invoked directly by humans. The directory must
be owned by root.
</p>
</DD>
<DT><b><a name="daemon_table_open_error_is_fatal">daemon_table_open_error_is_fatal</a>
(default: no)</b></DT><DD>
<p> How a Postfix daemon process handles errors while opening lookup
tables: gradual degradation or immediate termination. </p>
<dl>
<dt> <b> no </b> (default) </dt> <dd> <p> Gradual degradation: a
daemon process logs a message of type "error" and continues execution
with reduced functionality. Features that do not depend on the
unavailable table will work normally, while features that depend
on the table will result in a type "warning" message. <br> When
the <a href="postconf.5.html#notify_classes">notify_classes</a> parameter value contains the "data" class, the
Postfix SMTP server and client will report transcripts of sessions
with an error because a table is unavailable. </p> </dd>
<dt> <b> yes </b> (historical behavior) </dt> <dd> <p> Immediate
termination: a daemon process logs a type "fatal" message and
terminates immediately. This option reduces the number of possible
code paths through Postfix, and may therefore be slightly more
secure than the default. </p> </dd>
</dl>
<p> For the sake of sanity, the number of type "error" messages is
limited to 13 over the lifetime of a daemon process. </p>
<p> This feature is available in Postfix 2.9 and later. </p>
</DD>
<DT><b><a name="daemon_timeout">daemon_timeout</a>
(default: 18000s)</b></DT><DD>
<p> How much time a Postfix daemon process may take to handle a
request before it is terminated by a built-in watchdog timer. </p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="data_directory">data_directory</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> The directory with Postfix-writable data files (for example:
caches, pseudo-random numbers). This directory must be owned by
the <a href="postconf.5.html#mail_owner">mail_owner</a> account, and must not be shared with non-Postfix
software. </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="debug_peer_level">debug_peer_level</a>
(default: 2)</b></DT><DD>
<p> The increment in verbose logging level when a remote client or
server matches a pattern in the <a href="postconf.5.html#debug_peer_list">debug_peer_list</a> parameter. </p>
</DD>
<DT><b><a name="debug_peer_list">debug_peer_list</a>
(default: empty)</b></DT><DD>
<p> Optional list of remote client or server hostname or network
address patterns that cause the verbose logging level to increase
by the amount specified in $<a href="postconf.5.html#debug_peer_level">debug_peer_level</a>. </p>
<p> Specify domain names, network/netmask patterns, "/file/name"
patterns or "<a href="DATABASE_README.html">type:table</a>" lookup tables. The right-hand side result
from "<a href="DATABASE_README.html">type:table</a>" lookups is ignored. </p>
<p> Pattern matching of domain names is controlled by the presence
or absence of "<a href="postconf.5.html#debug_peer_list">debug_peer_list</a>" in the <a href="postconf.5.html#parent_domain_matches_subdomains">parent_domain_matches_subdomains</a>
parameter value. </p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#debug_peer_list">debug_peer_list</a> = 127.0.0.1
<a href="postconf.5.html#debug_peer_list">debug_peer_list</a> = example.com
</pre>
</DD>
<DT><b><a name="debugger_command">debugger_command</a>
(default: empty)</b></DT><DD>
<p>
The external command to execute when a Postfix daemon program is
invoked with the -D option.
</p>
<p>
Use "command .. & sleep 5" so that the debugger can attach before
the process marches on. If you use an X-based debugger, be sure to
set up your XAUTHORITY environment variable before starting Postfix.
</p>
<p>
Note: the command is subject to $name expansion, before it is
passed to the default command interpreter. Specify "$$" to
produce a single "$" character.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#debugger_command">debugger_command</a> =
PATH=/usr/bin:/usr/X11R6/bin
ddd $<a href="postconf.5.html#daemon_directory">daemon_directory</a>/$<a href="postconf.5.html#process_name">process_name</a> $<a href="postconf.5.html#process_id">process_id</a> & sleep 5
</pre>
</DD>
<DT><b><a name="default_database_type">default_database_type</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
The default database type for use in <a href="newaliases.1.html">newaliases(1)</a>, <a href="postalias.1.html">postalias(1)</a>
and <a href="postmap.1.html">postmap(1)</a> commands. On many UNIX systems the default type is
either <b>dbm</b> or <b>hash</b>. The default setting is frozen
when the Postfix system is built.
</p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#default_database_type">default_database_type</a> = hash
<a href="postconf.5.html#default_database_type">default_database_type</a> = dbm
</pre>
</DD>
<DT><b><a name="default_delivery_slot_cost">default_delivery_slot_cost</a>
(default: 5)</b></DT><DD>
<p>
How often the Postfix queue manager's scheduler is allowed to
preempt delivery of one message with another.
</p>
<p>
Each transport maintains a so-called "available delivery slot counter"
for each message. One message can be preempted by another one when
the other message can be delivered using no more delivery slots
(i.e., invocations of delivery agents) than the current message
counter has accumulated (or will eventually accumulate - see about
slot loans below). This parameter controls how often is the counter
incremented - it happens after each <a href="postconf.5.html#default_delivery_slot_cost">default_delivery_slot_cost</a>
recipients have been delivered.
</p>
<p>
The cost of 0 is used to disable the preempting scheduling completely.
The minimum value the scheduling algorithm can use is 2 - use it
if you want to maximize the message throughput rate. Although there
is no maximum, it doesn't make much sense to use values above say
50.
</p>
<p>
The only reason why the value of 2 is not the default is the way
this parameter affects the delivery of mailing-list mail. In the
worst case, their delivery can take somewhere between (cost+1/cost)
and (cost/cost-1) times more than if the preemptive scheduler was
disabled. The default value of 5 turns out to provide reasonable
message response times while making sure the mailing-list deliveries
are not extended by more than 20-25 percent even in the worst case.
</p>
<p> Use <a href="postconf.5.html#transport_delivery_slot_cost"><i>transport</i>_delivery_slot_cost</a> to specify a
transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a>
name of the message delivery transport.
</p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#default_delivery_slot_cost">default_delivery_slot_cost</a> = 0
<a href="postconf.5.html#default_delivery_slot_cost">default_delivery_slot_cost</a> = 2
</pre>
</DD>
<DT><b><a name="default_delivery_slot_discount">default_delivery_slot_discount</a>
(default: 50)</b></DT><DD>
<p>
The default value for transport-specific _delivery_slot_discount
settings.
</p>
<p>
This parameter speeds up the moment when a message preemption can
happen. Instead of waiting until the full amount of delivery slots
required is available, the preemption can happen when
transport_delivery_slot_discount percent of the required amount
plus transport_delivery_slot_loan still remains to be accumulated.
Note that the full amount will still have to be accumulated before
another preemption can take place later.
</p>
<p> Use <a href="postconf.5.html#transport_delivery_slot_discount"><i>transport</i>_delivery_slot_discount</a> to specify a
transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a>
name of the message delivery transport.
</p>
</DD>
<DT><b><a name="default_delivery_slot_loan">default_delivery_slot_loan</a>
(default: 3)</b></DT><DD>
<p>
The default value for transport-specific _delivery_slot_loan
settings.
</p>
<p>
This parameter speeds up the moment when a message preemption can
happen. Instead of waiting until the full amount of delivery slots
required is available, the preemption can happen when
transport_delivery_slot_discount percent of the required amount
plus transport_delivery_slot_loan still remains to be accumulated.
Note that the full amount will still have to be accumulated before
another preemption can take place later.
</p>
<p> Use <a href="postconf.5.html#transport_delivery_slot_loan"><i>transport</i>_delivery_slot_loan</a> to specify a
transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a>
name of the message delivery transport.
</p>
</DD>
<DT><b><a name="default_delivery_status_filter">default_delivery_status_filter</a>
(default: empty)</b></DT><DD>
<p> Optional filter to replace the delivery status code or explanatory
text of successful or unsuccessful deliveries. This does not allow
the replacement of a successful status code (2.X.X) with an
unsuccessful status code (4.X.X or 5.X.X) or vice versa. </p>
<p> Note: the (smtp|lmtp)_delivery_status_filter is applied only
once per recipient: when delivery is successful, when delivery is
rejected with 5XX, or when there are no more alternate MX or A
destinations. Use <a href="postconf.5.html#smtp_reply_filter">smtp_reply_filter</a> or <a href="postconf.5.html#lmtp_reply_filter">lmtp_reply_filter</a> to inspect
responses for all delivery attempts. </p>
<p> The following parameters can be used to implement a filter for
specific delivery agents: <a href="postconf.5.html#lmtp_delivery_status_filter">lmtp_delivery_status_filter</a>,
<a href="postconf.5.html#local_delivery_status_filter">local_delivery_status_filter</a>, <a href="postconf.5.html#pipe_delivery_status_filter">pipe_delivery_status_filter</a>,
<a href="postconf.5.html#smtp_delivery_status_filter">smtp_delivery_status_filter</a> or <a href="postconf.5.html#virtual_delivery_status_filter">virtual_delivery_status_filter</a>. These
parameters support the same filter syntax as described here. </p>
<p> Specify zero or more "<a href="DATABASE_README.html">type:table</a>" lookup table names, separated
by comma or whitespace. For each successful or unsuccessful delivery
to a recipient, the tables are queried in the specified order with
one line of text that is structured as follows: </p>
<blockquote>
enhanced-status-code SPACE explanatory-text
</blockquote>
<p> The first table match wins. The lookup result must have the
same structure as the query, a successful status code (2.X.X) must
be replaced with a successful status code, an unsuccessful status
code (4.X.X or 5.X.X) must be replaced with an unsuccessful status
code, and the explanatory text field must be non-empty. Other results
will result in a warning. </p>
<p> Example 1: convert specific soft TLS errors into hard errors,
by overriding the first number in the enhanced status code. </p>
<blockquote>
<pre>
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
<a href="postconf.5.html#smtp_delivery_status_filter">smtp_delivery_status_filter</a> = <a href="pcre_table.5.html">pcre</a>:/etc/postfix/smtp_dsn_filter
</pre>
</blockquote>
<blockquote>
<pre>
/etc/postfix/smtp_dsn_filter:
/^4(\.\d+\.\d+ TLS is required, but host \S+ refused to start TLS: .+)/
5$1
/^4(\.\d+\.\d+ TLS is required, but was not offered by host .+)/
5$1
# Do not change the following into hard bounces. They may
# result from a local configuration problem.
# 4.\d+.\d+ TLS is required, but our TLS engine is unavailable
# 4.\d+.\d+ TLS is required, but unavailable
# 4.\d+.\d+ Cannot start TLS: handshake failure
</pre>
</blockquote>
<p> Example 2: censor the per-recipient delivery status text so
that it does not reveal the destination command or filename
when a remote sender requests confirmation of successful delivery.
</p>
<blockquote>
<pre>
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
<a href="postconf.5.html#local_delivery_status_filter">local_delivery_status_filter</a> = <a href="pcre_table.5.html">pcre</a>:/etc/postfix/local_dsn_filter
</pre>
</blockquote>
<blockquote>
<pre>
/etc/postfix/local_dsn_filter:
/^(2\S+ delivered to file).+/ $1
/^(2\S+ delivered to command).+/ $1
</pre>
</blockquote>
<p> Notes: </p>
<ul>
<li> <p> This feature will NOT override the <a href="postconf.5.html#soft_bounce">soft_bounce</a> safety net. </p>
<li> <p> This feature will change the enhanced status code and text
that is logged to the maillog file, and that is reported to the
sender in delivery confirmation or non-delivery notifications.
</p>
</ul>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="default_destination_concurrency_failed_cohort_limit">default_destination_concurrency_failed_cohort_limit</a>
(default: 1)</b></DT><DD>
<p> How many pseudo-cohorts must suffer connection or handshake
failure before a specific destination is considered unavailable
(and further delivery is suspended). Specify zero to disable this
feature. A destination's pseudo-cohort failure count is reset each
time a delivery completes without connection or handshake failure
for that specific destination. </p>
<p> A pseudo-cohort is the number of deliveries equal to a destination's
delivery concurrency. </p>
<p> Use <a href="postconf.5.html#transport_destination_concurrency_failed_cohort_limit"><i>transport</i>_destination_concurrency_failed_cohort_limit</a> to specify
a transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a>
name of the message delivery transport. </p>
<p> This feature is available in Postfix 2.5. The default setting
is compatible with earlier Postfix versions. </p>
</DD>
<DT><b><a name="default_destination_concurrency_limit">default_destination_concurrency_limit</a>
(default: 20)</b></DT><DD>
<p>
The default maximal number of parallel deliveries to the same
destination. This is the default limit for delivery via the <a href="lmtp.8.html">lmtp(8)</a>,
<a href="pipe.8.html">pipe(8)</a>, <a href="smtp.8.html">smtp(8)</a> and <a href="virtual.8.html">virtual(8)</a> delivery agents.
With per-destination recipient limit > 1, a destination is a domain,
otherwise it is a recipient.
</p>
<p> Use <a href="postconf.5.html#transport_destination_concurrency_limit"><i>transport</i>_destination_concurrency_limit</a> to specify a
transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a>
name of the message delivery transport.
</p>
</DD>
<DT><b><a name="default_destination_concurrency_negative_feedback">default_destination_concurrency_negative_feedback</a>
(default: 1)</b></DT><DD>
<p> The per-destination amount of delivery concurrency negative
feedback, after a delivery completes with a connection or handshake
failure. Feedback values are in the range 0..1 inclusive. With
negative feedback, concurrency is decremented at the beginning of
a sequence of length 1/feedback. This is unlike positive feedback,
where concurrency is incremented at the end of a sequence of length
1/feedback. </p>
<p> As of Postfix version 2.5, negative feedback cannot reduce
delivery concurrency to zero. Instead, a destination is marked
dead (further delivery suspended) after the failed pseudo-cohort
count reaches $<a href="postconf.5.html#default_destination_concurrency_failed_cohort_limit">default_destination_concurrency_failed_cohort_limit</a>
(or $<a href="postconf.5.html#transport_destination_concurrency_failed_cohort_limit"><i>transport</i>_destination_concurrency_failed_cohort_limit</a>).
To make the scheduler completely immune to connection or handshake
failures, specify a zero feedback value and a zero failed pseudo-cohort
limit. </p>
<p> Specify one of the following forms: </p>
<dl>
<dt> <b><i>number</i> </b> </dt>
<dt> <b><i>number</i> / <i>number</i> </b> </dt>
<dd> Constant feedback. The value must be in the range 0..1 inclusive.
The default setting of "1" is compatible with Postfix versions
before 2.5, where a destination's delivery concurrency is throttled
down to zero (and further delivery suspended) after a single failed
pseudo-cohort. </dd>
<dt> <b><i>number</i> / concurrency </b> </dt>
<dd> Variable feedback of "<i>number</i> / (delivery concurrency)".
The <i>number</i> must be in the range 0..1 inclusive. With
<i>number</i> equal to "1", a destination's delivery concurrency
is decremented by 1 after each failed pseudo-cohort. </dd>
</dl>
<p> A pseudo-cohort is the number of deliveries equal to a destination's
delivery concurrency. </p>
<p> Use <a href="postconf.5.html#transport_destination_concurrency_negative_feedback"><i>transport</i>_destination_concurrency_negative_feedback</a>
to specify a transport-specific override, where <i>transport</i>
is the <a href="master.5.html">master.cf</a>
name of the message delivery transport. </p>
<p> This feature is available in Postfix 2.5. The default setting
is compatible with earlier Postfix versions. </p>
</DD>
<DT><b><a name="default_destination_concurrency_positive_feedback">default_destination_concurrency_positive_feedback</a>
(default: 1)</b></DT><DD>
<p> The per-destination amount of delivery concurrency positive
feedback, after a delivery completes without connection or handshake
failure. Feedback values are in the range 0..1 inclusive. The
concurrency increases until it reaches the per-destination maximal
concurrency limit. With positive feedback, concurrency is incremented
at the end of a sequence with length 1/feedback. This is unlike
negative feedback, where concurrency is decremented at the start
of a sequence of length 1/feedback. </p>
<p> Specify one of the following forms: </p>
<dl>
<dt> <b><i>number</i> </b> </dt>
<dt> <b><i>number</i> / <i>number</i> </b> </dt>
<dd> Constant feedback. The value must be in the range 0..1
inclusive. The default setting of "1" is compatible with Postfix
versions before 2.5, where a destination's delivery concurrency
doubles after each successful pseudo-cohort. </dd>
<dt> <b><i>number</i> / concurrency </b> </dt>
<dd> Variable feedback of "<i>number</i> / (delivery concurrency)".
The <i>number</i> must be in the range 0..1 inclusive. With
<i>number</i> equal to "1", a destination's delivery concurrency
is incremented by 1 after each successful pseudo-cohort. </dd>
</dl>
<p> A pseudo-cohort is the number of deliveries equal to a destination's
delivery concurrency. </p>
<p> Use <a href="postconf.5.html#transport_destination_concurrency_positive_feedback"><i>transport</i>_destination_concurrency_positive_feedback</a>
to specify a transport-specific override, where <i>transport</i>
is the <a href="master.5.html">master.cf</a> name of the message delivery transport. </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="default_destination_rate_delay">default_destination_rate_delay</a>
(default: 0s)</b></DT><DD>
<p> The default amount of delay that is inserted between individual
deliveries to the same destination; the resulting behavior depends
on the value of the corresponding per-destination recipient limit.
</p>
<ul>
<li> <p> With a corresponding per-destination recipient limit >
1, the rate delay specifies the time between deliveries to the
<i>same domain</i>. Different domains are delivered in parallel,
subject to the process limits specified in <a href="master.5.html">master.cf</a>. </p>
<li> <p> With a corresponding per-destination recipient limit equal
to 1, the rate delay specifies the time between deliveries to the
<i>same recipient</i>. Different recipients are delivered in
parallel, subject to the process limits specified in <a href="master.5.html">master.cf</a>.
</p>
</ul>
<p> To enable the delay, specify a non-zero time value (an integral
value plus an optional one-letter suffix that specifies the time
unit). </p>
<p> Time units: s (seconds), m (minutes), h (hours), d (days), w
(weeks). The default time unit is s (seconds). </p>
<p> NOTE: the delay is enforced by the queue manager. The delay
timer state does not survive "<b>postfix reload</b>" or "<b>postfix
stop</b>".
</p>
<p> Use <a href="postconf.5.html#transport_destination_rate_delay"><i>transport</i>_destination_rate_delay</a> to specify a
transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a>
name of the message delivery transport.
</p>
<p> NOTE: with a non-zero _destination_rate_delay, specify a
<a href="postconf.5.html#transport_destination_concurrency_failed_cohort_limit"><i>transport</i>_destination_concurrency_failed_cohort_limit</a> of 10
or more to prevent Postfix from deferring all mail for the same
destination after only one connection or handshake error. </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="default_destination_recipient_limit">default_destination_recipient_limit</a>
(default: 50)</b></DT><DD>
<p>
The default maximal number of recipients per message delivery.
This is the default limit for delivery via the <a href="lmtp.8.html">lmtp(8)</a>, <a href="pipe.8.html">pipe(8)</a>,
<a href="smtp.8.html">smtp(8)</a> and <a href="virtual.8.html">virtual(8)</a> delivery agents.
</p>
<p> Setting this parameter to a value of 1 affects email deliveries
as follows:</p>
<ul>
<li> <p> It changes the meaning of the corresponding per-destination
concurrency limit, from concurrency of deliveries to the <i>same
domain</i> into concurrency of deliveries to the <i>same recipient</i>.
Different recipients are delivered in parallel, subject to the
process limits specified in <a href="master.5.html">master.cf</a>. </p>
<li> <p> It changes the meaning of the corresponding per-destination
rate delay, from the delay between deliveries to the <i>same
domain</i> into the delay between deliveries to the <i>same
recipient</i>. Again, different recipients are delivered in parallel,
subject to the process limits specified in <a href="master.5.html">master.cf</a>. </p>
<li> <p> It changes the meaning of other corresponding per-destination
settings in a similar manner, from settings for delivery to the
<i>same domain</i> into settings for delivery to the <i>same
recipient</i>.
</ul>
<p> Use <a href="postconf.5.html#transport_destination_recipient_limit"><i>transport</i>_destination_recipient_limit</a> to specify a
transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a>
name of the message delivery transport.
</p>
</DD>
<DT><b><a name="default_extra_recipient_limit">default_extra_recipient_limit</a>
(default: 1000)</b></DT><DD>
<p>
The default value for the extra per-transport limit imposed on the
number of in-memory recipients. This extra recipient space is
reserved for the cases when the Postfix queue manager's scheduler
preempts one message with another and suddenly needs some extra
recipients slots for the chosen message in order to avoid performance
degradation.
</p>
<p> Use <a href="postconf.5.html#transport_extra_recipient_limit"><i>transport</i>_extra_recipient_limit</a> to specify a
transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a>
name of the message delivery transport.
</p>
</DD>
<DT><b><a name="default_filter_nexthop">default_filter_nexthop</a>
(default: empty)</b></DT><DD>
<p> When a <a href="postconf.5.html#content_filter">content_filter</a> or FILTER request specifies no explicit
next-hop destination, use $<a href="postconf.5.html#default_filter_nexthop">default_filter_nexthop</a> instead; when
that value is empty, use the domain in the recipient address.
Specify "<a href="postconf.5.html#default_filter_nexthop">default_filter_nexthop</a> = $<a href="postconf.5.html#myhostname">myhostname</a>" for compatibility
with Postfix version 2.6 and earlier, or specify an explicit next-hop
destination with each <a href="postconf.5.html#content_filter">content_filter</a> value or FILTER action. </p>
<p> This feature is available in Postfix 2.7 and later. </p>
</DD>
<DT><b><a name="default_minimum_delivery_slots">default_minimum_delivery_slots</a>
(default: 3)</b></DT><DD>
<p>
How many recipients a message must have in order to invoke the
Postfix queue manager's scheduling algorithm at all. Messages
which would never accumulate at least this many delivery slots
(subject to slot cost parameter as well) are never preempted.
</p>
<p> Use <a href="postconf.5.html#transport_minimum_delivery_slots"><i>transport</i>_minimum_delivery_slots</a> to specify a
transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a>
name of the message delivery transport.
</p>
</DD>
<DT><b><a name="default_privs">default_privs</a>
(default: nobody)</b></DT><DD>
<p>
The default rights used by the <a href="local.8.html">local(8)</a> delivery agent for delivery
to external file or command. These rights are used when delivery
is requested from an <a href="aliases.5.html">aliases(5)</a> file that is owned by <b>root</b>, or
when delivery is done on behalf of <b>root</b>. <b>DO NOT SPECIFY A
PRIVILEGED USER OR THE POSTFIX OWNER</b>.
</p>
</DD>
<DT><b><a name="default_process_limit">default_process_limit</a>
(default: 100)</b></DT><DD>
<p>
The default maximal number of Postfix child processes that provide
a given service. This limit can be overruled for specific services
in the <a href="master.5.html">master.cf</a> file.
</p>
</DD>
<DT><b><a name="default_rbl_reply">default_rbl_reply</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
The default Postfix SMTP server response template for a request that is
rejected by an RBL-based restriction. This template can be overruled
by specific entries in the optional <a href="postconf.5.html#rbl_reply_maps">rbl_reply_maps</a> lookup table.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
<p>
The template is subject to exactly one level of $name substitution:
</p>
<dl>
<dt><b>$client</b></dt>
<dd>The client hostname and IP address, formatted as name[address]. </dd>
<dt><b>$client_address</b></dt>
<dd>The client IP address. </dd>
<dt><b>$client_name</b></dt>
<dd>The client hostname or "unknown". See <a href="postconf.5.html#reject_unknown_client_hostname">reject_unknown_client_hostname</a>
for more details. </dd>
<dt><b>$reverse_client_name</b></dt>
<dd>The client hostname from address->name lookup, or "unknown".
See <a href="postconf.5.html#reject_unknown_reverse_client_hostname">reject_unknown_reverse_client_hostname</a> for more details. </dd>
<dt><b>$helo_name</b></dt>
<dd>The hostname given in HELO or EHLO command or empty string. </dd>
<dt><b>$rbl_class</b></dt>
<dd>The blacklisted entity type: Client host, Helo command, Sender
address, or Recipient address. </dd>
<dt><b>$rbl_code</b></dt>
<dd>The numerical SMTP response code, as specified with the
<a href="postconf.5.html#maps_rbl_reject_code">maps_rbl_reject_code</a> configuration parameter. Note: The numerical
SMTP response code is required, and must appear at the start of the
reply. With Postfix version 2.3 and later this information may be followed
by an <a href="http://tools.ietf.org/html/rfc3463">RFC 3463</a> enhanced status code. </dd>
<dt><b>$rbl_domain</b></dt>
<dd>The RBL domain where $rbl_what is blacklisted. </dd>
<dt><b>$rbl_reason</b></dt>
<dd>The reason why $rbl_what is blacklisted, or an empty string. </dd>
<dt><b>$rbl_what</b></dt>
<dd>The entity that is blacklisted (an IP address, a hostname, a domain
name, or an email address whose domain was blacklisted). </dd>
<dt><b>$recipient</b></dt>
<dd>The recipient address or <> in case of the null address. </dd>
<dt><b>$recipient_domain</b></dt>
<dd>The recipient domain or empty string. </dd>
<dt><b>$recipient_name</b></dt>
<dd>The recipient address localpart or <> in case of null address. </dd>
<dt><b>$sender</b></dt>
<dd>The sender address or <> in case of the null address. </dd>
<dt><b>$sender_domain</b></dt>
<dd>The sender domain or empty string. </dd>
<dt><b>$sender_name</b></dt>
<dd>The sender address localpart or <> in case of the null address. </dd>
<dt><b>${name?text}</b></dt>
<dd>Expands to `text' if $name is not empty. </dd>
<dt><b>${name:text}</b></dt>
<dd>Expands to `text' if $name is empty. </dd>
</dl>
<p>
Instead of $name you can also specify ${name} or $(name).
</p>
<p> Note: when an enhanced status code is specified in an RBL reply
template, it is subject to modification. The following transformations
are needed when the same RBL reply template is used for client,
helo, sender, or recipient access restrictions. </p>
<ul>
<li> <p> When rejecting a sender address, the Postfix SMTP server
will transform a recipient DSN status (e.g., 4.1.1-4.1.6) into the
corresponding sender DSN status, and vice versa. </p>
<li> <p> When rejecting non-address information (such as the HELO
command argument or the client hostname/address), the Postfix SMTP
server will transform a sender or recipient DSN status into a generic
non-address DSN status (e.g., 4.0.0). </p>
</ul>
</DD>
<DT><b><a name="default_recipient_limit">default_recipient_limit</a>
(default: 20000)</b></DT><DD>
<p>
The default per-transport upper limit on the number of in-memory
recipients. These limits take priority over the global
<a href="postconf.5.html#qmgr_message_recipient_limit">qmgr_message_recipient_limit</a> after the message has been assigned
to the respective transports. See also <a href="postconf.5.html#default_extra_recipient_limit">default_extra_recipient_limit</a>
and <a href="postconf.5.html#qmgr_message_recipient_minimum">qmgr_message_recipient_minimum</a>.
</p>
<p> Use <a href="postconf.5.html#transport_recipient_limit"><i>transport</i>_recipient_limit</a> to specify a
transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a>
name of the message delivery transport.
</p>
</DD>
<DT><b><a name="default_recipient_refill_delay">default_recipient_refill_delay</a>
(default: 5s)</b></DT><DD>
<p>
The default per-transport maximum delay between recipients refills.
When not all message recipients fit into the memory at once, keep loading
more of them at least once every this many seconds. This is used to
make sure the recipients are refilled in timely manner even when
$<a href="postconf.5.html#default_recipient_refill_limit">default_recipient_refill_limit</a> is too high for too slow deliveries.
</p>
<p> Use <a href="postconf.5.html#transport_recipient_refill_delay"><i>transport</i>_recipient_refill_delay</a> to specify a
transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a>
name of the message delivery transport.
</p>
<p> This feature is available in Postfix 2.4 and later. </p>
</DD>
<DT><b><a name="default_recipient_refill_limit">default_recipient_refill_limit</a>
(default: 100)</b></DT><DD>
<p>
The default per-transport limit on the number of recipients refilled at
once. When not all message recipients fit into the memory at once, keep
loading more of them in batches of at least this many at a time. See also
$<a href="postconf.5.html#default_recipient_refill_delay">default_recipient_refill_delay</a>, which may result in recipient batches
lower than this when this limit is too high for too slow deliveries.
</p>
<p> Use <a href="postconf.5.html#transport_recipient_refill_limit"><i>transport</i>_recipient_refill_limit</a> to specify a
transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a>
name of the message delivery transport.
</p>
<p> This feature is available in Postfix 2.4 and later. </p>
</DD>
<DT><b><a name="default_transport">default_transport</a>
(default: smtp)</b></DT><DD>
<p>
The default mail delivery transport and next-hop destination for
destinations that do not match $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>,
$<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>, $<a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a>, $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>,
or $<a href="postconf.5.html#relay_domains">relay_domains</a>. This information can be overruled with the
<a href="postconf.5.html#sender_dependent_default_transport_maps">sender_dependent_default_transport_maps</a> parameter and with the
<a href="transport.5.html">transport(5)</a> table. </p>
<p>
In order of decreasing precedence, the nexthop destination is taken
from $<a href="postconf.5.html#sender_dependent_default_transport_maps">sender_dependent_default_transport_maps</a>, $<a href="postconf.5.html#default_transport">default_transport</a>,
$<a href="postconf.5.html#sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a>, $<a href="postconf.5.html#relayhost">relayhost</a>, or from the recipient
domain.
</p>
<p>
Specify a string of the form <i>transport:nexthop</i>, where <i>transport</i>
is the name of a mail delivery transport defined in <a href="master.5.html">master.cf</a>.
The <i>:nexthop</i> destination is optional; its syntax is documented
in the manual page of the corresponding delivery agent.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#default_transport">default_transport</a> = uucp:relayhostname
</pre>
</DD>
<DT><b><a name="default_transport_rate_delay">default_transport_rate_delay</a>
(default: 0s)</b></DT><DD>
<p> The default amount of delay that is inserted between individual
deliveries over the same message delivery transport, regardless of
destination. If non-zero, all deliveries over the same message
delivery transport will happen one at a time. </p>
<p>Use <a href="postconf.5.html#transport_transport_rate_delay"><i>transport</i>_transport_rate_delay</a> to specify a
transport-specific override, where the initial <i>transport</i> is
the <a href="master.5.html">master.cf</a> name of the message delivery transport. </p>
<p> Example: throttle outbound SMTP mail to at most 3 deliveries
per minute. </p>
<pre>
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
smtp_transport_rate_delay = 20s
</pre>
<p> To enable the delay, specify a non-zero time value (an integral
value plus an optional one-letter suffix that specifies the time
unit). </p>
<p> Time units: s (seconds), m (minutes), h (hours), d (days), w
(weeks). The default time unit is s (seconds). </p>
<p> NOTE: the delay is enforced by the queue manager. </p>
<p> This feature is available in Postfix 3.1 and later. </p>
</DD>
<DT><b><a name="default_verp_delimiters">default_verp_delimiters</a>
(default: +=)</b></DT><DD>
<p> The two default VERP delimiter characters. These are used when
no explicit delimiters are specified with the SMTP XVERP command
or with the "<b>sendmail -V</b>" command-line option. Specify
characters that are allowed by the <a href="postconf.5.html#verp_delimiter_filter">verp_delimiter_filter</a> setting.
</p>
<p>
This feature is available in Postfix 1.1 and later.
</p>
</DD>
<DT><b><a name="defer_code">defer_code</a>
(default: 450)</b></DT><DD>
<p>
The numerical Postfix SMTP server response code when a remote SMTP
client request is rejected by the "defer" restriction.
</p>
<p>
Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc5321">RFC 5321</a>.
</p>
</DD>
<DT><b><a name="defer_service_name">defer_service_name</a>
(default: defer)</b></DT><DD>
<p>
The name of the defer service. This service is implemented by the
<a href="bounce.8.html">bounce(8)</a> daemon and maintains a record
of failed delivery attempts and generates non-delivery notifications.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="defer_transports">defer_transports</a>
(default: empty)</b></DT><DD>
<p>
The names of message delivery transports that should not deliver mail
unless someone issues "<b>sendmail -q</b>" or equivalent. Specify zero
or more names of mail delivery transports names that appear in the
first field of <a href="master.5.html">master.cf</a>.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#defer_transports">defer_transports</a> = smtp
</pre>
</DD>
<DT><b><a name="delay_logging_resolution_limit">delay_logging_resolution_limit</a>
(default: 2)</b></DT><DD>
<p> The maximal number of digits after the decimal point when logging
sub-second delay values. Specify a number in the range 0..6. </p>
<p> Large delay values are rounded off to an integral number seconds;
delay values below the <a href="postconf.5.html#delay_logging_resolution_limit">delay_logging_resolution_limit</a> are logged
as "0", and delay values under 100s are logged with at most two-digit
precision. </p>
<p> The format of the "delays=a/b/c/d" logging is as follows: </p>
<ul>
<li> a = time from message arrival to last <a href="QSHAPE_README.html#active_queue">active queue</a> entry
<li> b = time from last <a href="QSHAPE_README.html#active_queue">active queue</a> entry to connection setup
<li> c = time in connection setup, including DNS, EHLO and STARTTLS
<li> d = time in message transmission
</ul>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="delay_notice_recipient">delay_notice_recipient</a>
(default: postmaster)</b></DT><DD>
<p>
The recipient of postmaster notifications with the message headers
of mail that cannot be delivered within $<a href="postconf.5.html#delay_warning_time">delay_warning_time</a> time
units. </p>
<p>
See also: <a href="postconf.5.html#delay_warning_time">delay_warning_time</a>, <a href="postconf.5.html#notify_classes">notify_classes</a>.
</p>
</DD>
<DT><b><a name="delay_warning_time">delay_warning_time</a>
(default: 0h)</b></DT><DD>
<p>
The time after which the sender receives a copy of the message
headers of mail that is still queued. The <a href="postconf.5.html#confirm_delay_cleared">confirm_delay_cleared</a>
parameter controls sender notification when the delay clears up.
</p>
<p>
To enable this feature, specify a non-zero time value (an integral
value plus an optional one-letter suffix that specifies the time
unit).
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is h (hours).
</p>
<p>
See also: <a href="postconf.5.html#delay_notice_recipient">delay_notice_recipient</a>, <a href="postconf.5.html#notify_classes">notify_classes</a>, <a href="postconf.5.html#confirm_delay_cleared">confirm_delay_cleared</a>.
</p>
</DD>
<DT><b><a name="deliver_lock_attempts">deliver_lock_attempts</a>
(default: 20)</b></DT><DD>
<p>
The maximal number of attempts to acquire an exclusive lock on a
mailbox file or <a href="bounce.8.html">bounce(8)</a> logfile.
</p>
</DD>
<DT><b><a name="deliver_lock_delay">deliver_lock_delay</a>
(default: 1s)</b></DT><DD>
<p>
The time between attempts to acquire an exclusive lock on a mailbox
file or <a href="bounce.8.html">bounce(8)</a> logfile.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="destination_concurrency_feedback_debug">destination_concurrency_feedback_debug</a>
(default: no)</b></DT><DD>
<p> Make the queue manager's feedback algorithm verbose for performance
analysis purposes. </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="detect_8bit_encoding_header">detect_8bit_encoding_header</a>
(default: yes)</b></DT><DD>
<p> Automatically detect 8BITMIME body content by looking at
Content-Transfer-Encoding: message headers; historically, this
behavior was hard-coded to be "always on". </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="disable_dns_lookups">disable_dns_lookups</a>
(default: no)</b></DT><DD>
<p>
Disable DNS lookups in the Postfix SMTP and LMTP clients. When
disabled, hosts are looked up with the getaddrinfo() system
library routine which normally also looks in /etc/hosts. As of
Postfix 2.11, this parameter is deprecated; use <a href="postconf.5.html#smtp_dns_support_level">smtp_dns_support_level</a>
instead.
</p>
<p>
DNS lookups are enabled by default.
</p>
</DD>
<DT><b><a name="disable_mime_input_processing">disable_mime_input_processing</a>
(default: no)</b></DT><DD>
<p>
Turn off MIME processing while receiving mail. This means that no
special treatment is given to Content-Type: message headers, and
that all text after the initial message headers is considered to
be part of the message body.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
<p>
Mime input processing is enabled by default, and is needed in order
to recognize MIME headers in message content.
</p>
</DD>
<DT><b><a name="disable_mime_output_conversion">disable_mime_output_conversion</a>
(default: no)</b></DT><DD>
<p>
Disable the conversion of 8BITMIME format to 7BIT format. Mime
output conversion is needed when the destination does not advertise
8BITMIME support.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="disable_verp_bounces">disable_verp_bounces</a>
(default: no)</b></DT><DD>
<p>
Disable sending one bounce report per recipient.
</p>
<p>
The default, one per recipient, is what ezmlm needs.
</p>
<p>
This feature is available in Postfix 1.1 and later.
</p>
</DD>
<DT><b><a name="disable_vrfy_command">disable_vrfy_command</a>
(default: no)</b></DT><DD>
<p>
Disable the SMTP VRFY command. This stops some techniques used to
harvest email addresses.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#disable_vrfy_command">disable_vrfy_command</a> = no
</pre>
</DD>
<DT><b><a name="dns_ncache_ttl_fix_enable">dns_ncache_ttl_fix_enable</a>
(default: no)</b></DT><DD>
<p> Enable a workaround for future libc incompatibility. The Postfix
implementation of <a href="http://tools.ietf.org/html/rfc2308">RFC 2308</a> negative reply caching relies on the
promise that res_query() and res_search() invoke res_send(), which
returns the server response in an application buffer even if the
requested record does not exist. If this promise is broken, specify
"yes" to enable a workaround for DNS reputation lookups. </p>
<p>
This feature is available in Postfix 3.1 and later.
</p>
</DD>
<DT><b><a name="dnsblog_reply_delay">dnsblog_reply_delay</a>
(default: 0s)</b></DT><DD>
<p> A debugging aid to artificially delay DNS responses. </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="dnsblog_service_name">dnsblog_service_name</a>
(default: dnsblog)</b></DT><DD>
<p> The name of the <a href="dnsblog.8.html">dnsblog(8)</a> service entry in <a href="master.5.html">master.cf</a>. This
service performs DNS white/blacklist lookups. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="dont_remove">dont_remove</a>
(default: 0)</b></DT><DD>
<p>
Don't remove queue files and save them to the "saved" mail queue.
This is a debugging aid. To inspect the envelope information and
content of a Postfix queue file, use the <a href="postcat.1.html">postcat(1)</a> command.
</p>
</DD>
<DT><b><a name="double_bounce_sender">double_bounce_sender</a>
(default: double-bounce)</b></DT><DD>
<p> The sender address of postmaster notifications that are generated
by the mail system. All mail to this address is silently discarded,
in order to terminate mail bounce loops. </p>
</DD>
<DT><b><a name="duplicate_filter_limit">duplicate_filter_limit</a>
(default: 1000)</b></DT><DD>
<p> The maximal number of addresses remembered by the address
duplicate filter for <a href="aliases.5.html">aliases(5)</a> or <a href="virtual.5.html">virtual(5)</a> alias expansion, or
for <a href="showq.8.html">showq(8)</a> queue displays. </p>
</DD>
<DT><b><a name="empty_address_default_transport_maps_lookup_key">empty_address_default_transport_maps_lookup_key</a>
(default: <>)</b></DT><DD>
<p> The <a href="postconf.5.html#sender_dependent_default_transport_maps">sender_dependent_default_transport_maps</a> search string that
will be used instead of the null sender address. </p>
<p> This feature is available in Postfix 2.7 and later. </p>
</DD>
<DT><b><a name="empty_address_recipient">empty_address_recipient</a>
(default: MAILER-DAEMON)</b></DT><DD>
<p>
The recipient of mail addressed to the null address. Postfix does
not accept such addresses in SMTP commands, but they may still be
created locally as the result of configuration or software error.
</p>
</DD>
<DT><b><a name="empty_address_relayhost_maps_lookup_key">empty_address_relayhost_maps_lookup_key</a>
(default: <>)</b></DT><DD>
<p> The <a href="postconf.5.html#sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a> search string that will be
used instead of the null sender address. </p>
<p> This feature is available in Postfix 2.5 and later. With
earlier versions, <a href="postconf.5.html#sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a> lookups were
skipped for the null sender address. </p>
</DD>
<DT><b><a name="enable_errors_to">enable_errors_to</a>
(default: no)</b></DT><DD>
<p> Report mail delivery errors to the address specified with the
non-standard Errors-To: message header, instead of the envelope
sender address (this feature is removed with Postfix version 2.2, is
turned off by default with Postfix version 2.1, and is always turned on
with older Postfix versions). </p>
</DD>
<DT><b><a name="enable_idna2003_compatibility">enable_idna2003_compatibility</a>
(default: no)</b></DT><DD>
<p> Enable 'transitional' compatibility between IDNA2003 and IDNA2008,
when converting UTF-8 domain names to/from the ASCII form that is
used for DNS lookups. Specify "yes" for compatibility with Postfix
≤ 3.1 (not recommended). This affects the conversion of domain
names that contain for example the German sz and the Greek zeta.
See <a href="http://unicode.org/cldr/utility/idna.jsp">http://unicode.org/cldr/utility/idna.jsp</a> for more examples.
</p>
<p> This feature is available in Postfix 3.2 and later. </p>
</DD>
<DT><b><a name="enable_long_queue_ids">enable_long_queue_ids</a>
(default: no)</b></DT><DD>
<p> Enable long, non-repeating, queue IDs (queue file names). The
benefit of non-repeating names is simpler logfile analysis and
easier queue migration (there is no need to run "postsuper" to
change queue file names that don't match their message file inode
number). </p>
<p> Note: see below for how to convert long queue file names to
Postfix ≤ 2.8. </p>
<p> Changing the parameter value to "yes" has the following effects:
</p>
<ul>
<li> <p> Existing queue file names are not affected. </p>
<li> <p> New queue files are created with names such as 3Pt2mN2VXxznjll.
These are encoded in a 52-character alphabet that contains digits
(0-9), upper-case letters (B-Z) and lower-case letters (b-z). For
safety reasons the vowels (AEIOUaeiou) are excluded from the alphabet.
The name format is: 6 or more characters for the time in seconds,
4 characters for the time in microseconds, the 'z'; the remainder
is the file inode number encoded in the first 51 characters of the
52-character alphabet. </p>
<li> <p> New messages have a Message-ID header with
<i>queueID</i>@<i><a href="postconf.5.html#myhostname">myhostname</a></i>. </p>
<li> <p> The mailq (postqueue -p) output has a wider Queue ID column.
The number of whitespace-separated fields is not changed. <p>
<li> <p> The <a href="postconf.5.html#hash_queue_depth">hash_queue_depth</a> algorithm uses the first characters
of the queue file creation time in microseconds, after conversion
into hexadecimal representation. This produces the same queue hashing
behavior as if the queue file name was created with "<a href="postconf.5.html#enable_long_queue_ids">enable_long_queue_ids</a>
= no". </p>
</ul>
<p> Changing the parameter value to "no" has the following effects:
</p>
<ul>
<li> <p> Existing long queue file names are renamed to the short
form (while running "postfix reload" or "postsuper"). </p>
<li> <p> New queue files are created with names such as C3CD21F3E90
from a hexadecimal alphabet that contains digits (0-9) and upper-case
letters (A-F). The name format is: 5 characters for the time in
microseconds; the remainder is the file inode number. </p>
<li> <p> New messages have a Message-ID header with
<i>YYYYMMDDHHMMSS.queueid</i>@<i><a href="postconf.5.html#myhostname">myhostname</a></i>, where
<i>YYYYMMDDHHMMSS</i> are the year, month, day, hour, minute and
second.
<li> <p> The mailq (postqueue -p) output has the same format as
with Postfix ≤ 2.8. <p>
<li> <p> The <a href="postconf.5.html#hash_queue_depth">hash_queue_depth</a> algorithm uses the first characters
of the queue file name, with the hexadecimal representation of the
file creation time in microseconds. </p>
</ul>
<p> Before migration to Postfix ≤ 2.8, the following commands
are required to convert long queue file names into short names: </p>
<pre>
# postfix stop
# postconf <a href="postconf.5.html#enable_long_queue_ids">enable_long_queue_ids</a>=no
# postsuper
</pre>
<p> Repeat the postsuper command until it reports no more queue file
name changes. </p>
<p> This feature is available in Postfix 2.9 and later. </p>
</DD>
<DT><b><a name="enable_original_recipient">enable_original_recipient</a>
(default: yes)</b></DT><DD>
<p> Enable support for the original recipient address after an
address is rewritten to a different address (for example with
aliasing or with canonical mapping). </p>
<p> The original recipient address is used as follows: </p>
<dl>
<dt> Final delivery </dt> <dd> With "<a href="postconf.5.html#enable_original_recipient">enable_original_recipient</a> =
yes", the original recipient address is stored in the <b>X-Original-To</b>
message header. This header may be used to distinguish between
different recipients that share the same mailbox. </dd>
<dt> Recipient deduplication </dt> <dd> With "<a href="postconf.5.html#enable_original_recipient">enable_original_recipient</a>
= yes", the <a href="cleanup.8.html">cleanup(8)</a> daemon performs duplicate recipient elimination
based on the content of (original recipient, maybe-rewritten
recipient) pairs. Otherwise, the <a href="cleanup.8.html">cleanup(8)</a> daemon performs duplicate
recipient elimination based only on the maybe-rewritten recipient
address. </dd>
</dl>
<p> Note: with Postfix ≤ 3.2 the "setting <a href="postconf.5.html#enable_original_recipient">enable_original_recipient</a>
= <b>no</b>" breaks address verification for addresses that are
aliased or otherwise rewritten (Postfix is unable to store the
address verification result under the original probe destination
address; instead, it can store the result only under the rewritten
address). </p>
<p> This feature is available in Postfix 2.1 and later. Postfix
version 2.0 behaves as if this parameter is always set to <b>yes</b>.
Postfix versions before 2.0 have no support for the original recipient
address. </p>
</DD>
<DT><b><a name="error_notice_recipient">error_notice_recipient</a>
(default: postmaster)</b></DT><DD>
<p> The recipient of postmaster notifications about mail delivery
problems that are caused by policy, resource, software or protocol
errors. These notifications are enabled with the <a href="postconf.5.html#notify_classes">notify_classes</a>
parameter. </p>
</DD>
<DT><b><a name="error_service_name">error_service_name</a>
(default: error)</b></DT><DD>
<p>
The name of the <a href="error.8.html">error(8)</a> pseudo delivery agent. This service always
returns mail as undeliverable.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="execution_directory_expansion_filter">execution_directory_expansion_filter</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> Restrict the characters that the <a href="local.8.html">local(8)</a> delivery agent allows
in $name expansions of $<a href="postconf.5.html#command_execution_directory">command_execution_directory</a>. Characters
outside the allowed set are replaced by underscores. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="expand_owner_alias">expand_owner_alias</a>
(default: no)</b></DT><DD>
<p>
When delivering to an alias "<i>aliasname</i>" that has an
"owner-<i>aliasname</i>" companion alias, set the envelope sender
address to the expansion of the "owner-<i>aliasname</i>" alias.
Normally, Postfix sets the envelope sender address to the name of
the "owner-<i>aliasname</i>" alias.
</p>
</DD>
<DT><b><a name="export_environment">export_environment</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
The list of environment variables that a Postfix process will export
to non-Postfix processes. The TZ variable is needed for sane
time keeping on System-V-ish systems.
</p>
<p>
Specify a list of names and/or name=value pairs, separated by
whitespace or comma. Specify "{ name=value }" to protect whitespace
or comma in parameter values (whitespace after "{" and before "}"
is ignored). The form name=value is supported with Postfix version
2.1 and later; the use of {} is supported with Postfix 3.0 and
later. </p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#export_environment">export_environment</a> = TZ PATH=/bin:/usr/bin
</pre>
</DD>
<DT><b><a name="extract_recipient_limit">extract_recipient_limit</a>
(default: 10240)</b></DT><DD>
<p>
The maximal number of recipient addresses that Postfix will extract
from message headers when mail is submitted with "<b>sendmail -t</b>".
</p>
<p>
This feature was removed in Postfix version 2.1.
</p>
</DD>
<DT><b><a name="fallback_relay">fallback_relay</a>
(default: empty)</b></DT><DD>
<p>
Optional list of relay hosts for SMTP destinations that can't be
found or that are unreachable. With Postfix 2.3 this parameter
is renamed to <a href="postconf.5.html#smtp_fallback_relay">smtp_fallback_relay</a>. </p>
<p>
By default, mail is returned to the sender when a destination is
not found, and delivery is deferred when a destination is unreachable.
</p>
<p> The fallback relays must be SMTP destinations. Specify a domain,
host, host:port, [host]:port, [address] or [address]:port; the form
[host] turns off MX lookups. If you specify multiple SMTP
destinations, Postfix will try them in the specified order. </p>
<p> Note: before Postfix 2.2, do not use the <a href="postconf.5.html#fallback_relay">fallback_relay</a> feature
when relaying mail
for a backup or primary MX domain. Mail would loop between the
Postfix MX host and the <a href="postconf.5.html#fallback_relay">fallback_relay</a> host when the final destination
is unavailable. </p>
<ul>
<li> In <a href="postconf.5.html">main.cf</a> specify "<a href="postconf.5.html#relay_transport">relay_transport</a> = relay",
<li> In <a href="master.5.html">master.cf</a> specify "-o <a href="postconf.5.html#fallback_relay">fallback_relay</a> =" (i.e., empty) at
the end of the <tt>relay</tt> entry.
<li> In transport maps, specify "relay:<i>nexthop...</i>"
as the right-hand side for backup or primary MX domain entries.
</ul>
<p> Postfix version 2.2 and later will not use the <a href="postconf.5.html#fallback_relay">fallback_relay</a> feature
for destinations that it is MX host for.
</p>
</DD>
<DT><b><a name="fallback_transport">fallback_transport</a>
(default: empty)</b></DT><DD>
<p>
Optional message delivery transport that the <a href="local.8.html">local(8)</a> delivery
agent should use for names that are not found in the <a href="aliases.5.html">aliases(5)</a>
or UNIX password database.
</p>
<p> The precedence of <a href="local.8.html">local(8)</a> delivery features from high to low
is: aliases, .forward files, <a href="postconf.5.html#mailbox_transport_maps">mailbox_transport_maps</a>, <a href="postconf.5.html#mailbox_transport">mailbox_transport</a>,
<a href="postconf.5.html#mailbox_command_maps">mailbox_command_maps</a>, <a href="postconf.5.html#mailbox_command">mailbox_command</a>, <a href="postconf.5.html#home_mailbox">home_mailbox</a>, <a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a>,
<a href="postconf.5.html#fallback_transport_maps">fallback_transport_maps</a>, <a href="postconf.5.html#fallback_transport">fallback_transport</a> and <a href="postconf.5.html#luser_relay">luser_relay</a>. </p>
</DD>
<DT><b><a name="fallback_transport_maps">fallback_transport_maps</a>
(default: empty)</b></DT><DD>
<p> Optional lookup tables with per-recipient message delivery
transports for recipients that the <a href="local.8.html">local(8)</a> delivery agent could
not find in the <a href="aliases.5.html">aliases(5)</a> or UNIX password database. </p>
<p> The precedence of <a href="local.8.html">local(8)</a> delivery features from high to low
is: aliases, .forward files, <a href="postconf.5.html#mailbox_transport_maps">mailbox_transport_maps</a>, <a href="postconf.5.html#mailbox_transport">mailbox_transport</a>,
<a href="postconf.5.html#mailbox_command_maps">mailbox_command_maps</a>, <a href="postconf.5.html#mailbox_command">mailbox_command</a>, <a href="postconf.5.html#home_mailbox">home_mailbox</a>, <a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a>,
<a href="postconf.5.html#fallback_transport_maps">fallback_transport_maps</a>, <a href="postconf.5.html#fallback_transport">fallback_transport</a> and <a href="postconf.5.html#luser_relay">luser_relay</a>. </p>
<p> For safety reasons, this feature does not allow $number
substitutions in regular expression maps. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="fast_flush_domains">fast_flush_domains</a>
(default: $<a href="postconf.5.html#relay_domains">relay_domains</a>)</b></DT><DD>
<p>
Optional list of destinations that are eligible for per-destination
logfiles with mail that is queued to those destinations.
</p>
<p>
By default, Postfix maintains "fast flush" logfiles only for
destinations that the Postfix SMTP server is willing to relay to
(i.e. the default is: "<a href="postconf.5.html#fast_flush_domains">fast_flush_domains</a> = $<a href="postconf.5.html#relay_domains">relay_domains</a>"; see
the <a href="postconf.5.html#relay_domains">relay_domains</a> parameter in the <a href="postconf.5.html">postconf(5)</a> manual).
</p>
<p> Specify a list of hosts or domains, "/file/name" patterns or
"<a href="DATABASE_README.html">type:table</a>" lookup tables, separated by commas and/or whitespace.
Continue long lines by starting the next line with whitespace. A
"/file/name" pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>"
lookup table is matched when the domain or its parent domain appears
as lookup key. </p>
<p> Pattern matching of domain names is controlled by the presence
or absence of "<a href="postconf.5.html#fast_flush_domains">fast_flush_domains</a>" in the <a href="postconf.5.html#parent_domain_matches_subdomains">parent_domain_matches_subdomains</a>
parameter value. </p>
<p>
Specify "<a href="postconf.5.html#fast_flush_domains">fast_flush_domains</a> =" (i.e., empty) to disable the feature
altogether.
</p>
</DD>
<DT><b><a name="fast_flush_purge_time">fast_flush_purge_time</a>
(default: 7d)</b></DT><DD>
<p>
The time after which an empty per-destination "fast flush" logfile
is deleted.
</p>
<p>
You can specify the time as a number, or as a number followed by
a letter that indicates the time unit: s=seconds, m=minutes, h=hours,
d=days, w=weeks. The default time unit is days.
</p>
</DD>
<DT><b><a name="fast_flush_refresh_time">fast_flush_refresh_time</a>
(default: 12h)</b></DT><DD>
<p>
The time after which a non-empty but unread per-destination "fast
flush" logfile needs to be refreshed. The contents of a logfile
are refreshed by requesting delivery of all messages listed in the
logfile.
</p>
<p>
You can specify the time as a number, or as a number followed by
a letter that indicates the time unit: s=seconds, m=minutes, h=hours,
d=days, w=weeks. The default time unit is hours.
</p>
</DD>
<DT><b><a name="fault_injection_code">fault_injection_code</a>
(default: 0)</b></DT><DD>
<p>
Force specific internal tests to fail, to test the handling of
errors that are difficult to reproduce otherwise.
</p>
</DD>
<DT><b><a name="flush_service_name">flush_service_name</a>
(default: flush)</b></DT><DD>
<p>
The name of the <a href="flush.8.html">flush(8)</a> service. This service maintains per-destination
logfiles with the queue file names of mail that is queued for those
destinations.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="fork_attempts">fork_attempts</a>
(default: 5)</b></DT><DD>
<p> The maximal number of attempts to fork() a child process. </p>
</DD>
<DT><b><a name="fork_delay">fork_delay</a>
(default: 1s)</b></DT><DD>
<p> The delay between attempts to fork() a child process. </p>
<p> Time units: s (seconds), m (minutes), h (hours), d (days), w
(weeks). The default time unit is s (seconds). </p>
</DD>
<DT><b><a name="forward_expansion_filter">forward_expansion_filter</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
Restrict the characters that the <a href="local.8.html">local(8)</a> delivery agent allows in
$name expansions of $<a href="postconf.5.html#forward_path">forward_path</a>. Characters outside the
allowed set are replaced by underscores.
</p>
</DD>
<DT><b><a name="forward_path">forward_path</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> The <a href="local.8.html">local(8)</a> delivery agent search list for finding a .forward
file with user-specified delivery methods. The first file that is
found is used. </p>
<p> The following $name expansions are done on <a href="postconf.5.html#forward_path">forward_path</a> before
the search actually happens. The result of $name expansion is
filtered with the character set that is specified with the
<a href="postconf.5.html#forward_expansion_filter">forward_expansion_filter</a> parameter. </p>
<dl>
<dt><b>$user</b></dt>
<dd>The recipient's username. </dd>
<dt><b>$shell</b></dt>
<dd>The recipient's login shell pathname. </dd>
<dt><b>$home</b></dt>
<dd>The recipient's home directory. </dd>
<dt><b>$recipient</b></dt>
<dd>The full recipient address. </dd>
<dt><b>$extension</b></dt>
<dd>The optional recipient address extension. </dd>
<dt><b>$domain</b></dt>
<dd>The recipient domain. </dd>
<dt><b>$local</b></dt>
<dd>The entire recipient localpart. </dd>
<dt><b>$<a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a></b></dt>
<dd>The address extension delimiter that was found in the recipient
address (Postfix 2.11 and later), or the system-wide recipient
address extension delimiter (Postfix 2.10 and earlier). </dd>
<dt><b>${name?value}</b></dt>
<dd>Expands to <i>value</i> when <i>$name</i> is non-empty. </dd>
<dt><b>${name:value}</b></dt>
<dd>Expands to <i>value</i> when <i>$name</i> is empty. </dd>
</dl>
<p>
Instead of $name you can also specify ${name} or $(name).
</p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#forward_path">forward_path</a> = /var/forward/$user
<a href="postconf.5.html#forward_path">forward_path</a> =
/var/forward/$user/.forward$<a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a>$extension,
/var/forward/$user/.forward
</pre>
</DD>
<DT><b><a name="frozen_delivered_to">frozen_delivered_to</a>
(default: yes)</b></DT><DD>
<p> Update the <a href="local.8.html">local(8)</a> delivery agent's idea of the Delivered-To:
address (see <a href="postconf.5.html#prepend_delivered_header">prepend_delivered_header</a>) only once, at the start of
a delivery attempt; do not update the Delivered-To: address while
expanding aliases or .forward files. </p>
<p> This feature is available in Postfix 2.3 and later. With older
Postfix releases, the behavior is as if this parameter is set to
"no". The old setting can be expensive with deeply nested aliases
or .forward files. When an alias or .forward file changes the
Delivered-To: address, it ties up one queue file and one cleanup
process instance while mail is being forwarded. </p>
</DD>
<DT><b><a name="hash_queue_depth">hash_queue_depth</a>
(default: 1)</b></DT><DD>
<p>
The number of subdirectory levels for queue directories listed with
the <a href="postconf.5.html#hash_queue_names">hash_queue_names</a> parameter. Queue hashing is implemented by
creating one or more levels of directories with one-character names.
Originally, these directory names were equal to the first characters
of the queue file name, with the hexadecimal representation of the
file creation time in microseconds. </p>
<p> With long queue file names, queue hashing produces the same
results as with short names. The file creation time in microseconds
is converted into hexadecimal form before the result is used for
queue hashing. The base 16 encoding gives finer control over the
number of subdirectories than is possible with the base 52 encoding
of long queue file names. </p>
<p>
After changing the <a href="postconf.5.html#hash_queue_names">hash_queue_names</a> or <a href="postconf.5.html#hash_queue_depth">hash_queue_depth</a> parameter,
execute the command "<b>postfix reload</b>".
</p>
</DD>
<DT><b><a name="hash_queue_names">hash_queue_names</a>
(default: deferred, defer)</b></DT><DD>
<p>
The names of queue directories that are split across multiple
subdirectory levels.
</p>
<p> Before Postfix version 2.2, the default list of hashed queues
was significantly larger. Claims about improvements in file system
technology suggest that hashing of the <a href="QSHAPE_README.html#incoming_queue">incoming</a> and <a href="QSHAPE_README.html#active_queue">active queues</a>
is no longer needed. Fewer hashed directories speed up the time
needed to restart Postfix. </p>
<p>
After changing the <a href="postconf.5.html#hash_queue_names">hash_queue_names</a> or <a href="postconf.5.html#hash_queue_depth">hash_queue_depth</a> parameter,
execute the command "<b>postfix reload</b>".
</p>
</DD>
<DT><b><a name="header_address_token_limit">header_address_token_limit</a>
(default: 10240)</b></DT><DD>
<p>
The maximal number of address tokens are allowed in an address
message header. Information that exceeds the limit is discarded.
The limit is enforced by the <a href="cleanup.8.html">cleanup(8)</a> server.
</p>
</DD>
<DT><b><a name="header_checks">header_checks</a>
(default: empty)</b></DT><DD>
<p>
Optional lookup tables for content inspection of primary non-MIME
message headers, as specified in the <a href="header_checks.5.html">header_checks(5)</a> manual page.
</p>
</DD>
<DT><b><a name="header_from_format">header_from_format</a>
(default: standard)</b></DT><DD>
<p> The format of the Postfix-generated <b>From:</b> header. This
setting affects the appearance of 'full name' information when a
local program such as /bin/mail submits a message without From:
header through the Postfix <a href="sendmail.1.html">sendmail(1)</a> command. </p>
<p> Specify one of the following: </p>
<dl>
<dt><b>standard</b> (default)</dt> <dd> Produce a header formatted
as "<b>From:</b> <i>name</i><b> <</b><i>address</i><b>></b>".
This is the default as of Postfix 3.3.</dd>
<dt><b>obsolete</b></dt> <dd>Produce a header formatted as "<b>From:</b>
<i>address</i> <b>(</b><i>name</i><b>)</b>". This is the behavior
prior to Postfix 3.3. </dd>
</dl>
<p> Notes: </p>
<ul>
<li> <p> Postfix generates the format "<b>From:</b> <i>address</i>"
when <i>name</i> information is unavailable or the envelope sender
address is empty. This is the same behavior as prior to Postfix
3.3. </p>
<li> <p> In the <b>standard</b> form, the <i>name</i> will be quoted
if it contains <b>specials</b> as defined in <a href="http://tools.ietf.org/html/rfc5322">RFC 5322</a>, or the "!%"
address operators. </p>
<li> <p> The Postfix <a href="sendmail.1.html">sendmail(1)</a> command gets <i>name</i> information
from the <b>-F</b> command-line option, from the <b>NAME</b>
environment variable, or from the UNIX password file. </p>
</ul>
<p> This feature is available in Postfix 3.3 and later. </p>
</DD>
<DT><b><a name="header_size_limit">header_size_limit</a>
(default: 102400)</b></DT><DD>
<p>
The maximal amount of memory in bytes for storing a message header.
If a header is larger, the excess is discarded. The limit is
enforced by the <a href="cleanup.8.html">cleanup(8)</a> server.
</p>
</DD>
<DT><b><a name="helpful_warnings">helpful_warnings</a>
(default: yes)</b></DT><DD>
<p>
Log warnings about problematic configuration settings, and provide
helpful suggestions.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="home_mailbox">home_mailbox</a>
(default: empty)</b></DT><DD>
<p>
Optional pathname of a mailbox file relative to a <a href="local.8.html">local(8)</a> user's
home directory.
</p>
<p>
Specify a pathname ending in "/" for qmail-style delivery.
</p>
<p> The precedence of <a href="local.8.html">local(8)</a> delivery features from high to low
is: aliases, .forward files, <a href="postconf.5.html#mailbox_transport_maps">mailbox_transport_maps</a>, <a href="postconf.5.html#mailbox_transport">mailbox_transport</a>,
<a href="postconf.5.html#mailbox_command_maps">mailbox_command_maps</a>, <a href="postconf.5.html#mailbox_command">mailbox_command</a>, <a href="postconf.5.html#home_mailbox">home_mailbox</a>, <a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a>,
<a href="postconf.5.html#fallback_transport_maps">fallback_transport_maps</a>, <a href="postconf.5.html#fallback_transport">fallback_transport</a> and <a href="postconf.5.html#luser_relay">luser_relay</a>. </p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#home_mailbox">home_mailbox</a> = Mailbox
<a href="postconf.5.html#home_mailbox">home_mailbox</a> = Maildir/
</pre>
</DD>
<DT><b><a name="hopcount_limit">hopcount_limit</a>
(default: 50)</b></DT><DD>
<p>
The maximal number of Received: message headers that is allowed
in the primary message headers. A message that exceeds the limit
is bounced, in order to stop a mailer loop.
</p>
</DD>
<DT><b><a name="html_directory">html_directory</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
The location of Postfix HTML files that describe how to build,
configure or operate a specific Postfix subsystem or feature.
</p>
</DD>
<DT><b><a name="ignore_mx_lookup_error">ignore_mx_lookup_error</a>
(default: no)</b></DT><DD>
<p> Ignore DNS MX lookups that produce no response. By default,
the Postfix SMTP client defers delivery and tries again after some
delay. This behavior is required by the SMTP standard. </p>
<p>
Specify "<a href="postconf.5.html#ignore_mx_lookup_error">ignore_mx_lookup_error</a> = yes" to force a DNS A record
lookup instead. This violates the SMTP standard and can result in
mis-delivery of mail.
</p>
</DD>
<DT><b><a name="import_environment">import_environment</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> The list of environment parameters that a privileged Postfix
process will import from a non-Postfix parent process, or name=value
environment overrides. Unprivileged utilities will enforce the
name=value overrides, but otherwise will not change their process
environment. Examples of relevant parameters: </p>
<dl>
<dt><b>TZ</b></dt>
<dd>May be needed for sane time keeping on most System-V-ish systems.
</dd>
<dt><b>DISPLAY</b></dt>
<dd>Needed for debugging Postfix daemons with an X-windows debugger. </dd>
<dt><b>XAUTHORITY</b></dt>
<dd>Needed for debugging Postfix daemons with an X-windows debugger. </dd>
<dt><b>MAIL_CONFIG</b></dt>
<dd>Needed to make "<b>postfix -c</b>" work. </dd>
</dl>
<p> Specify a list of names and/or name=value pairs, separated by
whitespace or comma. Specify "{ name=value }" to protect whitespace
or comma in parameter values (whitespace after "{" and before "}"
is ignored). The form name=value is supported with Postfix version
2.1 and later; the use of {} is supported with Postfix 3.0 and
later. </p>
</DD>
<DT><b><a name="in_flow_delay">in_flow_delay</a>
(default: 1s)</b></DT><DD>
<p> Time to pause before accepting a new message, when the message
arrival rate exceeds the message delivery rate. This feature is
turned on by default (it's disabled on SCO UNIX due to an SCO bug).
</p>
<p>
With the default 100 Postfix SMTP server process limit, "<a href="postconf.5.html#in_flow_delay">in_flow_delay</a>
= 1s" limits the mail inflow to 100 messages per second above the
number of messages delivered per second.
</p>
<p>
Specify 0 to disable the feature. Valid delays are 0..10.
</p>
</DD>
<DT><b><a name="inet_interfaces">inet_interfaces</a>
(default: all)</b></DT><DD>
<p> The network interface addresses that this mail system receives
mail on. Specify "all" to receive mail on all network
interfaces (default), and "loopback-only" to receive mail
on loopback network interfaces only (Postfix version 2.2 and later). The
parameter also controls delivery of mail to <tt>user@[ip.address]</tt>.
</p>
<p>
Note 1: you need to stop and start Postfix when this parameter changes.
</p>
<p> Note 2: address information may be enclosed inside <tt>[]</tt>,
but this form is not required here. </p>
<p> When <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> specifies just one IPv4 and/or IPv6 address
that is not a loopback address, the Postfix SMTP client will use
this address as the IP source address for outbound mail. Support
for IPv6 is available in Postfix version 2.2 and later. </p>
<p>
On a multi-homed firewall with separate Postfix instances listening on the
"inside" and "outside" interfaces, this can prevent each instance from
being able to reach remote SMTP servers on the "other side" of the
firewall. Setting
<a href="postconf.5.html#smtp_bind_address">smtp_bind_address</a> to 0.0.0.0 avoids the potential problem for
IPv4, and setting <a href="postconf.5.html#smtp_bind_address6">smtp_bind_address6</a> to :: solves the problem
for IPv6. </p>
<p>
A better solution for multi-homed firewalls is to leave <a href="postconf.5.html#inet_interfaces">inet_interfaces</a>
at the default value and instead use explicit IP addresses in
the <a href="master.5.html">master.cf</a> SMTP server definitions. This preserves the Postfix
SMTP client's
loop detection, by ensuring that each side of the firewall knows that the
other IP address is still the same host. Setting $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> to a
single IPv4 and/or IPV6 address is primarily useful with virtual
hosting of domains on
secondary IP addresses, when each IP address serves a different domain
(and has a different $<a href="postconf.5.html#myhostname">myhostname</a> setting). </p>
<p>
See also the <a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a> parameter, for network addresses that
are forwarded to Postfix by way of a proxy or address translator.
</p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> = all (DEFAULT)
<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> = loopback-only (Postfix version 2.2 and later)
<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> = 127.0.0.1
<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> = 127.0.0.1, [::1] (Postfix version 2.2 and later)
<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> = 192.168.1.2, 127.0.0.1
</pre>
</DD>
<DT><b><a name="inet_protocols">inet_protocols</a>
(default: all)</b></DT><DD>
<p> The Internet protocols Postfix will attempt to use when making
or accepting connections. Specify one or more of "ipv4"
or "ipv6", separated by whitespace or commas. The form
"all" is equivalent to "ipv4, ipv6" or "ipv4", depending
on whether the operating system implements IPv6. </p>
<p> With Postfix 2.8 and earlier the default is "ipv4". For backwards
compatibility with these releases, the Postfix 2.9 and later upgrade
procedure appends an explicit "<a href="postconf.5.html#inet_protocols">inet_protocols</a> = ipv4" setting to
<a href="postconf.5.html">main.cf</a> when no explicit setting is present. This compatibility
workaround will be phased out as IPv6 deployment becomes more common.
</p>
<p> This feature is available in Postfix 2.2 and later. </p>
<p> Note: you MUST stop and start Postfix after changing this
parameter. </p>
<p> On systems that pre-date IPV6_V6ONLY support (<a href="http://tools.ietf.org/html/rfc3493">RFC 3493</a>), an
IPv6 server will also accept IPv4 connections, even when IPv4 is
turned off with the <a href="postconf.5.html#inet_protocols">inet_protocols</a> parameter. On systems with
IPV6_V6ONLY support, Postfix will use separate server sockets for
IPv6 and IPv4, and each will accept only connections for the
corresponding protocol. </p>
<p> When IPv4 support is enabled via the <a href="postconf.5.html#inet_protocols">inet_protocols</a> parameter,
Postfix will look up DNS type A records, and will convert
IPv4-in-IPv6 client IP addresses (::ffff:1.2.3.4) to their original
IPv4 form (1.2.3.4). The latter is needed on hosts that pre-date
IPV6_V6ONLY support (<a href="http://tools.ietf.org/html/rfc3493">RFC 3493</a>). </p>
<p> When IPv6 support is enabled via the <a href="postconf.5.html#inet_protocols">inet_protocols</a> parameter,
Postfix will do DNS type AAAA record lookups. </p>
<p> When both IPv4 and IPv6 support are enabled, the Postfix SMTP
client will choose the protocol as specified with the
<a href="postconf.5.html#smtp_address_preference">smtp_address_preference</a> parameter. Postfix versions before 2.8
attempt to connect via IPv6 before attempting to use IPv4. </p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#inet_protocols">inet_protocols</a> = ipv4
<a href="postconf.5.html#inet_protocols">inet_protocols</a> = all (DEFAULT)
<a href="postconf.5.html#inet_protocols">inet_protocols</a> = ipv6
<a href="postconf.5.html#inet_protocols">inet_protocols</a> = ipv4, ipv6
</pre>
</DD>
<DT><b><a name="initial_destination_concurrency">initial_destination_concurrency</a>
(default: 5)</b></DT><DD>
<p>
The initial per-destination concurrency level for parallel delivery
to the same destination.
With per-destination recipient limit > 1, a destination is a domain,
otherwise it is a recipient.
</p>
<p> Use <a href="postconf.5.html#transport_initial_destination_concurrency"><i>transport</i>_initial_destination_concurrency</a> to specify
a transport-specific override, where <i>transport</i> is the <a href="master.5.html">master.cf</a>
name of the message delivery transport (Postfix 2.5 and later). </p>
<p>
Warning: with concurrency of 1, one bad message can be enough to
block all mail to a site.
</p>
</DD>
<DT><b><a name="internal_mail_filter_classes">internal_mail_filter_classes</a>
(default: empty)</b></DT><DD>
<p> What categories of Postfix-generated mail are subject to
before-queue content inspection by <a href="postconf.5.html#non_smtpd_milters">non_smtpd_milters</a>, <a href="postconf.5.html#header_checks">header_checks</a>
and <a href="postconf.5.html#body_checks">body_checks</a>. Specify zero or more of the following, separated
by whitespace or comma. </p>
<dl>
<dt><b>bounce</b></dt> <dd> Inspect the content of delivery
status notifications. </dd>
<dt><b>notify</b></dt> <dd> Inspect the content of postmaster
notifications by the <a href="smtp.8.html">smtp(8)</a> and <a href="smtpd.8.html">smtpd(8)</a> processes. </dd>
</dl>
<p> NOTE: It's generally not safe to enable content inspection of
Postfix-generated email messages. The user is warned. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="invalid_hostname_reject_code">invalid_hostname_reject_code</a>
(default: 501)</b></DT><DD>
<p>
The numerical Postfix SMTP server response code when the client
HELO or EHLO command parameter is rejected by the <a href="postconf.5.html#reject_invalid_helo_hostname">reject_invalid_helo_hostname</a>
restriction.
</p>
<p>
Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc5321">RFC 5321</a>.
</p>
</DD>
<DT><b><a name="ipc_idle">ipc_idle</a>
(default: version dependent)</b></DT><DD>
<p>
The time after which a client closes an idle internal communication
channel. The purpose is to allow Postfix daemon processes to
terminate voluntarily after they become idle. This is used, for
example, by the Postfix address resolving and rewriting clients.
</p>
<p> With Postfix 2.4 the default value was reduced from 100s to 5s. </p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="ipc_timeout">ipc_timeout</a>
(default: 3600s)</b></DT><DD>
<p>
The time limit for sending or receiving information over an internal
communication channel. The purpose is to break out of deadlock
situations. If the time limit is exceeded the software aborts with a
fatal error.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="ipc_ttl">ipc_ttl</a>
(default: 1000s)</b></DT><DD>
<p>
The time after which a client closes an active internal communication
channel. The purpose is to allow Postfix daemon processes to
terminate voluntarily
after reaching their client limit. This is used, for example, by
the Postfix address resolving and rewriting clients.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="line_length_limit">line_length_limit</a>
(default: 2048)</b></DT><DD>
<p> Upon input, long lines are chopped up into pieces of at most
this length; upon delivery, long lines are reconstructed. </p>
</DD>
<DT><b><a name="lmdb_map_size">lmdb_map_size</a>
(default: 16777216)</b></DT><DD>
<p>
The initial OpenLDAP LMDB database size limit in bytes. Each time
a database becomes full, its size limit is doubled.
</p>
<p>
This feature is available in Postfix 2.11 and later.
</p>
</DD>
<DT><b><a name="lmtp_address_preference">lmtp_address_preference</a>
(default: ipv6)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_address_preference">smtp_address_preference</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="lmtp_address_verify_target">lmtp_address_verify_target</a>
(default: rcpt)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_address_verify_target">smtp_address_verify_target</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="lmtp_assume_final">lmtp_assume_final</a>
(default: no)</b></DT><DD>
<p> When a remote LMTP server announces no DSN support, assume that
the
server performs final delivery, and send "delivered" delivery status
notifications instead of "relayed". The default setting is backwards
compatible to avoid the infinitesimal possibility of breaking
existing LMTP-based content filters. </p>
</DD>
<DT><b><a name="lmtp_balance_inet_protocols">lmtp_balance_inet_protocols</a>
(default: yes)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_balance_inet_protocols">smtp_balance_inet_protocols</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 3.3 and later. </p>
</DD>
<DT><b><a name="lmtp_bind_address">lmtp_bind_address</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_bind_address">smtp_bind_address</a> configuration
parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_bind_address6">lmtp_bind_address6</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_bind_address6">smtp_bind_address6</a> configuration
parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_body_checks">lmtp_body_checks</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_body_checks">smtp_body_checks</a> configuration
parameter. See there for details. </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="lmtp_cache_connection">lmtp_cache_connection</a>
(default: yes)</b></DT><DD>
<p>
Keep Postfix LMTP client connections open for up to $<a href="postconf.5.html#max_idle">max_idle</a>
seconds. When the LMTP client receives a request for the same
connection the connection is reused.
</p>
<p> This parameter is available in Postfix version 2.2 and earlier.
With Postfix version 2.3 and later, see <a href="postconf.5.html#lmtp_connection_cache_on_demand">lmtp_connection_cache_on_demand</a>,
<a href="postconf.5.html#lmtp_connection_cache_destinations">lmtp_connection_cache_destinations</a>, or <a href="postconf.5.html#lmtp_connection_reuse_time_limit">lmtp_connection_reuse_time_limit</a>.
</p>
<p>
The effectiveness of cached connections will be determined by the
number of remote LMTP servers in use, and the concurrency limit specified
for the Postfix LMTP client. Cached connections are closed under any of
the following conditions:
</p>
<ul>
<li> The Postfix LMTP client idle time limit is reached. This limit is
specified with the Postfix <a href="postconf.5.html#max_idle">max_idle</a> configuration parameter.
<li> A delivery request specifies a different destination than the
one currently cached.
<li> The per-process limit on the number of delivery requests is
reached. This limit is specified with the Postfix <a href="postconf.5.html#max_use">max_use</a>
configuration parameter.
<li> Upon the onset of another delivery request, the remote LMTP server
associated with the current session does not respond to the RSET
command.
</ul>
<p>
Most of these limitations have been with the Postfix
a connection cache that is shared among multiple LMTP client
programs.
</p>
</DD>
<DT><b><a name="lmtp_cname_overrides_servername">lmtp_cname_overrides_servername</a>
(default: yes)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_cname_overrides_servername">smtp_cname_overrides_servername</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_connect_timeout">lmtp_connect_timeout</a>
(default: 0s)</b></DT><DD>
<p> The Postfix LMTP client time limit for completing a TCP connection, or
zero (use the operating system built-in time limit). When no
connection can be made within the deadline, the LMTP client tries
the next address on the mail exchanger list. </p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#lmtp_connect_timeout">lmtp_connect_timeout</a> = 30s
</pre>
</DD>
<DT><b><a name="lmtp_connection_cache_destinations">lmtp_connection_cache_destinations</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_connection_cache_destinations">smtp_connection_cache_destinations</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_connection_cache_on_demand">lmtp_connection_cache_on_demand</a>
(default: yes)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_connection_cache_on_demand">smtp_connection_cache_on_demand</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_connection_cache_time_limit">lmtp_connection_cache_time_limit</a>
(default: 2s)</b></DT><DD>
<p> The LMTP-specific version of the
<a href="postconf.5.html#smtp_connection_cache_time_limit">smtp_connection_cache_time_limit</a> configuration parameter.
See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_connection_reuse_count_limit">lmtp_connection_reuse_count_limit</a>
(default: 0)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_connection_reuse_count_limit">smtp_connection_reuse_count_limit</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.11 and later. </p>
</DD>
<DT><b><a name="lmtp_connection_reuse_time_limit">lmtp_connection_reuse_time_limit</a>
(default: 300s)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_connection_reuse_time_limit">smtp_connection_reuse_time_limit</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_data_done_timeout">lmtp_data_done_timeout</a>
(default: 600s)</b></DT><DD>
<p> The Postfix LMTP client time limit for sending the LMTP ".",
and for receiving the remote LMTP server response. When no response
is received within the deadline, a warning is logged that the mail
may be delivered multiple times. </p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="lmtp_data_init_timeout">lmtp_data_init_timeout</a>
(default: 120s)</b></DT><DD>
<p>
The Postfix LMTP client time limit for sending the LMTP DATA command,
and
for receiving the remote LMTP server response.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="lmtp_data_xfer_timeout">lmtp_data_xfer_timeout</a>
(default: 180s)</b></DT><DD>
<p>
The Postfix LMTP client time limit for sending the LMTP message
content.
When the connection stalls for more than $<a href="postconf.5.html#lmtp_data_xfer_timeout">lmtp_data_xfer_timeout</a>
the LMTP client terminates the transfer.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="lmtp_defer_if_no_mx_address_found">lmtp_defer_if_no_mx_address_found</a>
(default: no)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_defer_if_no_mx_address_found">smtp_defer_if_no_mx_address_found</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_delivery_status_filter">lmtp_delivery_status_filter</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_delivery_status_filter">smtp_delivery_status_filter</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="lmtp_destination_concurrency_limit">lmtp_destination_concurrency_limit</a>
(default: $<a href="postconf.5.html#default_destination_concurrency_limit">default_destination_concurrency_limit</a>)</b></DT><DD>
<p> The maximal number of parallel deliveries to the same destination
via the lmtp message delivery transport. This limit is enforced by
the queue manager. The message delivery transport name is the first
field in the entry in the <a href="master.5.html">master.cf</a> file. </p>
</DD>
<DT><b><a name="lmtp_destination_recipient_limit">lmtp_destination_recipient_limit</a>
(default: $<a href="postconf.5.html#default_destination_recipient_limit">default_destination_recipient_limit</a>)</b></DT><DD>
<p> The maximal number of recipients per message for the lmtp
message delivery transport. This limit is enforced by the queue
manager. The message delivery transport name is the first field in
the entry in the <a href="master.5.html">master.cf</a> file. </p>
<p> Setting this parameter to a value of 1 changes the meaning of
<a href="postconf.5.html#lmtp_destination_concurrency_limit">lmtp_destination_concurrency_limit</a> from concurrency per domain into
concurrency per recipient. </p>
</DD>
<DT><b><a name="lmtp_discard_lhlo_keyword_address_maps">lmtp_discard_lhlo_keyword_address_maps</a>
(default: empty)</b></DT><DD>
<p> Lookup tables, indexed by the remote LMTP server address, with
case insensitive lists of LHLO keywords (pipelining, starttls,
auth, etc.) that the Postfix LMTP client will ignore in the LHLO
response
from a remote LMTP server. See <a href="postconf.5.html#lmtp_discard_lhlo_keywords">lmtp_discard_lhlo_keywords</a> for
details. The table is not indexed by hostname for consistency with
<a href="postconf.5.html#smtpd_discard_ehlo_keyword_address_maps">smtpd_discard_ehlo_keyword_address_maps</a>. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_discard_lhlo_keywords">lmtp_discard_lhlo_keywords</a>
(default: empty)</b></DT><DD>
<p> A case insensitive list of LHLO keywords (pipelining, starttls,
auth, etc.) that the Postfix LMTP client will ignore in the LHLO
response
from a remote LMTP server. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
<p> Notes: </p>
<ul>
<li> <p> Specify the <b>silent-discard</b> pseudo keyword to prevent
this action from being logged. </p>
<li> <p> Use the <a href="postconf.5.html#lmtp_discard_lhlo_keyword_address_maps">lmtp_discard_lhlo_keyword_address_maps</a> feature to
discard LHLO keywords selectively. </p>
</ul>
</DD>
<DT><b><a name="lmtp_dns_reply_filter">lmtp_dns_reply_filter</a>
(default: empty)</b></DT><DD>
<p> Optional filter for Postfix LMTP client DNS lookup results.
See <a href="postconf.5.html#smtp_dns_reply_filter">smtp_dns_reply_filter</a> for details including an example. </p>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="lmtp_dns_resolver_options">lmtp_dns_resolver_options</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_dns_resolver_options">smtp_dns_resolver_options</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="lmtp_dns_support_level">lmtp_dns_support_level</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_dns_support_level">smtp_dns_support_level</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.11 and later. </p>
</DD>
<DT><b><a name="lmtp_enforce_tls">lmtp_enforce_tls</a>
(default: no)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_enforce_tls">smtp_enforce_tls</a> configuration
parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_fallback_relay">lmtp_fallback_relay</a>
(default: empty)</b></DT><DD>
<p> Optional list of relay hosts for LMTP destinations that can't be
found or that are unreachable. In <a href="postconf.5.html">main.cf</a> elements are separated by
whitespace or commas. </p>
<p> By default, mail is returned to the sender when a destination is not
found, and delivery is deferred when a destination is unreachable. </p>
<p> The fallback relays must be TCP destinations, specified without
a leading "inet:" prefix. Specify a host or host:port. Since MX
lookups do not apply with LMTP, there is no need to use the "[host]" or
"[host]:port" forms. If you specify multiple LMTP destinations, Postfix
will try them in the specified order. </p>
<p>
This feature is available in Postfix 3.1 and later.
</p>
</DD>
<DT><b><a name="lmtp_generic_maps">lmtp_generic_maps</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_generic_maps">smtp_generic_maps</a> configuration
parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_header_checks">lmtp_header_checks</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_header_checks">smtp_header_checks</a> configuration
parameter. See there for details. </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="lmtp_host_lookup">lmtp_host_lookup</a>
(default: dns)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_host_lookup">smtp_host_lookup</a> configuration
parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_lhlo_name">lmtp_lhlo_name</a>
(default: $<a href="postconf.5.html#myhostname">myhostname</a>)</b></DT><DD>
<p>
The hostname to send in the LMTP LHLO command.
</p>
<p>
The default value is the machine hostname. Specify a hostname or
[ip.add.re.ss].
</p>
<p>
This information can be specified in the <a href="postconf.5.html">main.cf</a> file for all LMTP
clients, or it can be specified in the <a href="master.5.html">master.cf</a> file for a specific
client, for example:
</p>
<blockquote>
<pre>
/etc/postfix/<a href="master.5.html">master.cf</a>:
mylmtp ... lmtp -o <a href="postconf.5.html#lmtp_lhlo_name">lmtp_lhlo_name</a>=foo.bar.com
</pre>
</blockquote>
<p>
This feature is available in Postfix 2.3 and later.
</p>
</DD>
<DT><b><a name="lmtp_lhlo_timeout">lmtp_lhlo_timeout</a>
(default: 300s)</b></DT><DD>
<p> The Postfix LMTP client time limit for sending the LHLO command,
and for receiving the initial remote LMTP server response. </p>
<p> Time units: s (seconds), m (minutes), h (hours), d (days), w
(weeks). The default time unit is s (seconds). </p>
</DD>
<DT><b><a name="lmtp_line_length_limit">lmtp_line_length_limit</a>
(default: 990)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_line_length_limit">smtp_line_length_limit</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_mail_timeout">lmtp_mail_timeout</a>
(default: 300s)</b></DT><DD>
<p>
The Postfix LMTP client time limit for sending the MAIL FROM command,
and for receiving the remote LMTP server response.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="lmtp_mime_header_checks">lmtp_mime_header_checks</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_mime_header_checks">smtp_mime_header_checks</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="lmtp_mx_address_limit">lmtp_mx_address_limit</a>
(default: 5)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_mx_address_limit">smtp_mx_address_limit</a> configuration
parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_mx_session_limit">lmtp_mx_session_limit</a>
(default: 2)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_mx_session_limit">smtp_mx_session_limit</a> configuration
parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_nested_header_checks">lmtp_nested_header_checks</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_nested_header_checks">smtp_nested_header_checks</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="lmtp_per_record_deadline">lmtp_per_record_deadline</a>
(default: no)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_per_record_deadline">smtp_per_record_deadline</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.9 and later. </p>
</DD>
<DT><b><a name="lmtp_pix_workaround_delay_time">lmtp_pix_workaround_delay_time</a>
(default: 10s)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_pix_workaround_delay_time">smtp_pix_workaround_delay_time</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_pix_workaround_maps">lmtp_pix_workaround_maps</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_pix_workaround_maps">smtp_pix_workaround_maps</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.4 and later. </p>
</DD>
<DT><b><a name="lmtp_pix_workaround_threshold_time">lmtp_pix_workaround_threshold_time</a>
(default: 500s)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_pix_workaround_threshold_time">smtp_pix_workaround_threshold_time</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_pix_workarounds">lmtp_pix_workarounds</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the smtp_pix_workaround
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.4 and later. </p>
</DD>
<DT><b><a name="lmtp_quit_timeout">lmtp_quit_timeout</a>
(default: 300s)</b></DT><DD>
<p>
The Postfix LMTP client time limit for sending the QUIT command,
and for receiving the remote LMTP server response.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="lmtp_quote_rfc821_envelope">lmtp_quote_rfc821_envelope</a>
(default: yes)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_quote_rfc821_envelope">smtp_quote_rfc821_envelope</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_randomize_addresses">lmtp_randomize_addresses</a>
(default: yes)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_randomize_addresses">smtp_randomize_addresses</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_rcpt_timeout">lmtp_rcpt_timeout</a>
(default: 300s)</b></DT><DD>
<p>
The Postfix LMTP client time limit for sending the RCPT TO command,
and for receiving the remote LMTP server response.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="lmtp_reply_filter">lmtp_reply_filter</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_reply_filter">smtp_reply_filter</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.7 and later. </p>
</DD>
<DT><b><a name="lmtp_rset_timeout">lmtp_rset_timeout</a>
(default: 20s)</b></DT><DD>
<p> The Postfix LMTP client time limit for sending the RSET command,
and for receiving the remote LMTP server response. The LMTP client
sends RSET in
order to finish a recipient address probe, or to verify that a
cached connection is still alive. </p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="lmtp_sasl_auth_cache_name">lmtp_sasl_auth_cache_name</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_sasl_auth_cache_name">smtp_sasl_auth_cache_name</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="lmtp_sasl_auth_cache_time">lmtp_sasl_auth_cache_time</a>
(default: 90d)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_sasl_auth_cache_time">smtp_sasl_auth_cache_time</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="lmtp_sasl_auth_enable">lmtp_sasl_auth_enable</a>
(default: no)</b></DT><DD>
<p>
Enable SASL authentication in the Postfix LMTP client.
</p>
</DD>
<DT><b><a name="lmtp_sasl_auth_soft_bounce">lmtp_sasl_auth_soft_bounce</a>
(default: yes)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_sasl_auth_soft_bounce">smtp_sasl_auth_soft_bounce</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="lmtp_sasl_mechanism_filter">lmtp_sasl_mechanism_filter</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_sasl_mechanism_filter">smtp_sasl_mechanism_filter</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_sasl_password_maps">lmtp_sasl_password_maps</a>
(default: empty)</b></DT><DD>
<p>
Optional Postfix LMTP client lookup tables with one username:password entry
per host or domain. If a remote host or domain has no username:password
entry, then the Postfix LMTP client will not attempt to authenticate
to the remote host.
</p>
</DD>
<DT><b><a name="lmtp_sasl_path">lmtp_sasl_path</a>
(default: empty)</b></DT><DD>
<p> Implementation-specific information that is passed through to
the SASL plug-in implementation that is selected with
<b><a href="postconf.5.html#lmtp_sasl_type">lmtp_sasl_type</a></b>. Typically this specifies the name of a
configuration file or rendezvous point. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_sasl_security_options">lmtp_sasl_security_options</a>
(default: noplaintext, noanonymous)</b></DT><DD>
<p> SASL security options; as of Postfix 2.3 the list of available
features depends on the SASL client implementation that is selected
with <b><a href="postconf.5.html#lmtp_sasl_type">lmtp_sasl_type</a></b>. </p>
<p> The following security features are defined for the <b>cyrus</b>
client SASL implementation: </p>
<dl>
<dt><b>noplaintext</b></dt>
<dd>Disallow authentication methods that use plaintext passwords. </dd>
<dt><b>noactive</b></dt>
<dd>Disallow authentication methods that are vulnerable to non-dictionary
active attacks. </dd>
<dt><b>nodictionary</b></dt>
<dd>Disallow authentication methods that are vulnerable to passive
dictionary attack. </dd>
<dt><b>noanonymous</b></dt>
<dd>Disallow anonymous logins. </dd>
</dl>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#lmtp_sasl_security_options">lmtp_sasl_security_options</a> = noplaintext
</pre>
</DD>
<DT><b><a name="lmtp_sasl_tls_security_options">lmtp_sasl_tls_security_options</a>
(default: $<a href="postconf.5.html#lmtp_sasl_security_options">lmtp_sasl_security_options</a>)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_sasl_tls_security_options">smtp_sasl_tls_security_options</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_sasl_tls_verified_security_options">lmtp_sasl_tls_verified_security_options</a>
(default: $<a href="postconf.5.html#lmtp_sasl_tls_security_options">lmtp_sasl_tls_security_options</a>)</b></DT><DD>
<p> The LMTP-specific version of the
<a href="postconf.5.html#smtp_sasl_tls_verified_security_options">smtp_sasl_tls_verified_security_options</a> configuration parameter.
See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_sasl_type">lmtp_sasl_type</a>
(default: cyrus)</b></DT><DD>
<p> The SASL plug-in type that the Postfix LMTP client should use
for authentication. The available types are listed with the
"<b>postconf -A</b>" command. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_send_dummy_mail_auth">lmtp_send_dummy_mail_auth</a>
(default: no)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_send_dummy_mail_auth">smtp_send_dummy_mail_auth</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.9 and later. </p>
</DD>
<DT><b><a name="lmtp_send_xforward_command">lmtp_send_xforward_command</a>
(default: no)</b></DT><DD>
<p>
Send an XFORWARD command to the remote LMTP server when the LMTP LHLO
server response announces XFORWARD support. This allows an <a href="lmtp.8.html">lmtp(8)</a>
delivery agent, used for content filter message injection, to
forward the name, address, protocol and HELO name of the original
client to the content filter and downstream queuing LMTP server.
Before you change the value to yes, it is best to make sure that
your content filter supports this command.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="lmtp_sender_dependent_authentication">lmtp_sender_dependent_authentication</a>
(default: no)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_sender_dependent_authentication">smtp_sender_dependent_authentication</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_skip_5xx_greeting">lmtp_skip_5xx_greeting</a>
(default: yes)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_skip_5xx_greeting">smtp_skip_5xx_greeting</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_skip_quit_response">lmtp_skip_quit_response</a>
(default: no)</b></DT><DD>
<p>
Wait for the response to the LMTP QUIT command.
</p>
</DD>
<DT><b><a name="lmtp_starttls_timeout">lmtp_starttls_timeout</a>
(default: 300s)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_starttls_timeout">smtp_starttls_timeout</a> configuration
parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_tcp_port">lmtp_tcp_port</a>
(default: 24)</b></DT><DD>
<p>
The default TCP port that the Postfix LMTP client connects to.
Specify a symbolic name (see services(5)) or a numeric port.
</p>
</DD>
<DT><b><a name="lmtp_tls_CAfile">lmtp_tls_CAfile</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_CAfile">smtp_tls_CAfile</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_CApath">lmtp_tls_CApath</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_CApath">smtp_tls_CApath</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_block_early_mail_reply">lmtp_tls_block_early_mail_reply</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_block_early_mail_reply">smtp_tls_block_early_mail_reply</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.7 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_cert_file">lmtp_tls_cert_file</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_ciphers">lmtp_tls_ciphers</a>
(default: medium)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a> configuration
parameter. See there for details. </p>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_dcert_file">lmtp_tls_dcert_file</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_dcert_file">smtp_tls_dcert_file</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_dkey_file">lmtp_tls_dkey_file</a>
(default: $<a href="postconf.5.html#lmtp_tls_dcert_file">lmtp_tls_dcert_file</a>)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_dkey_file">smtp_tls_dkey_file</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_eccert_file">lmtp_tls_eccert_file</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_eccert_file">smtp_tls_eccert_file</a> configuration
parameter. See there for details. </p>
<p> This feature is available in Postfix 2.6 and later, when Postfix is
compiled and linked with OpenSSL 1.0.0 or later. </p>
</DD>
<DT><b><a name="lmtp_tls_eckey_file">lmtp_tls_eckey_file</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_eckey_file">smtp_tls_eckey_file</a> configuration
parameter. See there for details. </p>
<p> This feature is available in Postfix 2.6 and later, when Postfix is
compiled and linked with OpenSSL 1.0.0 or later. </p>
</DD>
<DT><b><a name="lmtp_tls_enforce_peername">lmtp_tls_enforce_peername</a>
(default: yes)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_enforce_peername">smtp_tls_enforce_peername</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_exclude_ciphers">lmtp_tls_exclude_ciphers</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_fingerprint_cert_match">lmtp_tls_fingerprint_cert_match</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_fingerprint_cert_match">smtp_tls_fingerprint_cert_match</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_fingerprint_digest">lmtp_tls_fingerprint_digest</a>
(default: md5)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_force_insecure_host_tlsa_lookup">lmtp_tls_force_insecure_host_tlsa_lookup</a>
(default: no)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_force_insecure_host_tlsa_lookup">smtp_tls_force_insecure_host_tlsa_lookup</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.11 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_key_file">lmtp_tls_key_file</a>
(default: $<a href="postconf.5.html#lmtp_tls_cert_file">lmtp_tls_cert_file</a>)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_key_file">smtp_tls_key_file</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_loglevel">lmtp_tls_loglevel</a>
(default: 0)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_loglevel">smtp_tls_loglevel</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a>
(default: medium)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_mandatory_exclude_ciphers">lmtp_tls_mandatory_exclude_ciphers</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_mandatory_exclude_ciphers">smtp_tls_mandatory_exclude_ciphers</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_mandatory_protocols">lmtp_tls_mandatory_protocols</a>
(default: !SSLv2, !SSLv3)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_note_starttls_offer">lmtp_tls_note_starttls_offer</a>
(default: no)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_note_starttls_offer">smtp_tls_note_starttls_offer</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_per_site">lmtp_tls_per_site</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> configuration
parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_policy_maps">lmtp_tls_policy_maps</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_protocols">lmtp_tls_protocols</a>
(default: !SSLv2, !SSLv3)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> configuration
parameter. See there for details. </p>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_scert_verifydepth">lmtp_tls_scert_verifydepth</a>
(default: 9)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_scert_verifydepth">smtp_tls_scert_verifydepth</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_secure_cert_match">lmtp_tls_secure_cert_match</a>
(default: nexthop)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_secure_cert_match">smtp_tls_secure_cert_match</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_security_level">lmtp_tls_security_level</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> configuration
parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_session_cache_database">lmtp_tls_session_cache_database</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_session_cache_database">smtp_tls_session_cache_database</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_session_cache_timeout">lmtp_tls_session_cache_timeout</a>
(default: 3600s)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_session_cache_timeout">smtp_tls_session_cache_timeout</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_trust_anchor_file">lmtp_tls_trust_anchor_file</a>
(default: empty)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_trust_anchor_file">smtp_tls_trust_anchor_file</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.11 and later. </p>
</DD>
<DT><b><a name="lmtp_tls_verify_cert_match">lmtp_tls_verify_cert_match</a>
(default: hostname)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_tls_verify_cert_match">smtp_tls_verify_cert_match</a>
configuration parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_use_tls">lmtp_use_tls</a>
(default: no)</b></DT><DD>
<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_use_tls">smtp_use_tls</a> configuration
parameter. See there for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="lmtp_xforward_timeout">lmtp_xforward_timeout</a>
(default: 300s)</b></DT><DD>
<p>
The Postfix LMTP client time limit for sending the XFORWARD command,
and for receiving the remote LMTP server response.
</p>
<p>
In case of problems the client does NOT try the next address on
the mail exchanger list.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="local_command_shell">local_command_shell</a>
(default: empty)</b></DT><DD>
<p>
Optional shell program for <a href="local.8.html">local(8)</a> delivery to non-Postfix command.
By default, non-Postfix commands are executed directly; commands
are given to given to the default shell (typically, /bin/sh) only
when they contain shell meta characters or shell built-in commands.
</p>
<p> "sendmail's restricted shell" (smrsh) is what most people will
use in order to restrict what programs can be run from e.g. .forward
files (smrsh is part of the Sendmail distribution). </p>
<p> Note: when a shell program is specified, it is invoked even
when the command contains no shell built-in commands or meta
characters. </p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#local_command_shell">local_command_shell</a> = /some/where/smrsh -c
<a href="postconf.5.html#local_command_shell">local_command_shell</a> = /bin/bash -c
</pre>
</DD>
<DT><b><a name="local_delivery_status_filter">local_delivery_status_filter</a>
(default: $<a href="postconf.5.html#default_delivery_status_filter">default_delivery_status_filter</a>)</b></DT><DD>
<p> Optional filter for the <a href="local.8.html">local(8)</a> delivery agent to change the
status code or explanatory text of successful or unsuccessful
deliveries. See <a href="postconf.5.html#default_delivery_status_filter">default_delivery_status_filter</a> for details. </p>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="local_destination_concurrency_limit">local_destination_concurrency_limit</a>
(default: 2)</b></DT><DD>
<p> The maximal number of parallel deliveries via the local mail
delivery transport to the same recipient (when
"<a href="postconf.5.html#local_destination_recipient_limit">local_destination_recipient_limit</a> = 1") or the maximal number of
parallel deliveries to the same <a href="ADDRESS_CLASS_README.html#local_domain_class">local domain</a> (when
"<a href="postconf.5.html#local_destination_recipient_limit">local_destination_recipient_limit</a> > 1"). This limit is enforced by
the queue manager. The message delivery transport name is the first
field in the entry in the <a href="master.5.html">master.cf</a> file. </p>
<p> A low limit of 2 is recommended, just in case someone has an
expensive shell command in a .forward file or in an alias (e.g.,
a mailing list manager). You don't want to run lots of those at
the same time. </p>
</DD>
<DT><b><a name="local_destination_recipient_limit">local_destination_recipient_limit</a>
(default: 1)</b></DT><DD>
<p> The maximal number of recipients per message delivery via the
local mail delivery transport. This limit is enforced by the queue
manager. The message delivery transport name is the first field in
the entry in the <a href="master.5.html">master.cf</a> file. </p>
<p> Setting this parameter to a value > 1 changes the meaning of
<a href="postconf.5.html#local_destination_concurrency_limit">local_destination_concurrency_limit</a> from concurrency per recipient
into concurrency per domain. </p>
</DD>
<DT><b><a name="local_header_rewrite_clients">local_header_rewrite_clients</a>
(default: <a href="postconf.5.html#permit_inet_interfaces">permit_inet_interfaces</a>)</b></DT><DD>
<p> Rewrite message header addresses in mail from these clients and
update incomplete addresses with the domain name in $<a href="postconf.5.html#myorigin">myorigin</a> or
$<a href="postconf.5.html#mydomain">mydomain</a>; either don't rewrite message headers from other clients
at all, or rewrite message headers and update incomplete addresses
with the domain specified in the <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a>
parameter. </p>
<p> See the <a href="postconf.5.html#append_at_myorigin">append_at_myorigin</a> and <a href="postconf.5.html#append_dot_mydomain">append_dot_mydomain</a> parameters
for details of how domain names are appended to incomplete addresses.
</p>
<p> Specify a list of zero or more of the following: </p>
<dl>
<dt><b><a href="postconf.5.html#permit_inet_interfaces">permit_inet_interfaces</a></b></dt>
<dd> Append the domain name in $<a href="postconf.5.html#myorigin">myorigin</a> or $<a href="postconf.5.html#mydomain">mydomain</a> when the
client IP address matches $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>. This is enabled by
default. </dd>
<dt><b><a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a></b></dt>
<dd> Append the domain name in $<a href="postconf.5.html#myorigin">myorigin</a> or $<a href="postconf.5.html#mydomain">mydomain</a> when the
client IP address matches any network or network address listed in
$<a href="postconf.5.html#mynetworks">mynetworks</a>. This setting will not prevent remote mail header
address rewriting when mail from a remote client is forwarded by
a neighboring system. </dd>
<dt><b><a href="postconf.5.html#permit_sasl_authenticated">permit_sasl_authenticated</a> </b></dt>
<dd> Append the domain name in $<a href="postconf.5.html#myorigin">myorigin</a> or $<a href="postconf.5.html#mydomain">mydomain</a> when the
client is successfully authenticated via the <a href="http://tools.ietf.org/html/rfc4954">RFC 4954</a> (AUTH)
protocol. </dd>
<dt><b><a href="postconf.5.html#permit_tls_clientcerts">permit_tls_clientcerts</a> </b></dt>
<dd> Append the domain name in $<a href="postconf.5.html#myorigin">myorigin</a> or $<a href="postconf.5.html#mydomain">mydomain</a> when the
remote SMTP client TLS certificate fingerprint or public key fingerprint
(Postfix 2.9 and later) is listed in $<a href="postconf.5.html#relay_clientcerts">relay_clientcerts</a>.
The fingerprint digest algorithm is configurable via the
<a href="postconf.5.html#smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a> parameter (hard-coded as md5 prior to
Postfix version 2.5). </dd>
<dt><b><a href="postconf.5.html#permit_tls_all_clientcerts">permit_tls_all_clientcerts</a> </b></dt>
<dd> Append the domain name in $<a href="postconf.5.html#myorigin">myorigin</a> or $<a href="postconf.5.html#mydomain">mydomain</a> when the
remote SMTP client TLS certificate is successfully verified, regardless of
whether it is listed on the server, and regardless of the certifying
authority. </dd>
<dt><b><a name="check_address_map">check_address_map</a> <i><a href="DATABASE_README.html">type:table</a></i> </b></dt>
<dt><b><i><a href="DATABASE_README.html">type:table</a></i> </b></dt>
<dd> Append the domain name in $<a href="postconf.5.html#myorigin">myorigin</a> or $<a href="postconf.5.html#mydomain">mydomain</a> when the
client IP address matches the specified lookup table.
The lookup result is ignored, and no subnet lookup is done. This
is suitable for, e.g., pop-before-smtp lookup tables. </dd>
</dl>
<p> Examples: </p>
<p> The Postfix < 2.2 backwards compatible setting: always rewrite
message headers, and always append my own domain to incomplete
header addresses. </p>
<blockquote>
<pre>
<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = <a href="DATABASE_README.html#types">static</a>:all
</pre>
</blockquote>
<p> The purist (and default) setting: rewrite headers only in mail
from Postfix sendmail and in SMTP mail from this machine. </p>
<blockquote>
<pre>
<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = <a href="postconf.5.html#permit_inet_interfaces">permit_inet_interfaces</a>
</pre>
</blockquote>
<p> The intermediate setting: rewrite header addresses and append
$<a href="postconf.5.html#myorigin">myorigin</a> or $<a href="postconf.5.html#mydomain">mydomain</a> information only with mail from Postfix
sendmail, from local clients, or from authorized SMTP clients. </p>
<p> Note: this setting will not prevent remote mail header address
rewriting when mail from a remote client is forwarded by a neighboring
system. </p>
<blockquote>
<pre>
<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>,
<a href="postconf.5.html#permit_sasl_authenticated">permit_sasl_authenticated</a> <a href="postconf.5.html#permit_tls_clientcerts">permit_tls_clientcerts</a>
<a href="postconf.5.html#check_address_map">check_address_map</a> <a href="DATABASE_README.html#types">hash</a>:/etc/postfix/pop-before-smtp
</pre>
</blockquote>
</DD>
<DT><b><a name="local_recipient_maps">local_recipient_maps</a>
(default: <a href="proxymap.8.html">proxy</a>:unix:passwd.byname $<a href="postconf.5.html#alias_maps">alias_maps</a>)</b></DT><DD>
<p> Lookup tables with all names or addresses of local recipients:
a recipient address is local when its domain matches $<a href="postconf.5.html#mydestination">mydestination</a>,
$<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>. Specify @domain as a
wild-card for domains that do not have a valid recipient list.
Technically, tables listed with $<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> are used as
lists: Postfix needs to know only if a lookup string is found or
not, but it does not use the result from table lookup. </p>
<p>
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found.
</p>
<p>
If this parameter is non-empty (the default), then the Postfix SMTP
server will reject mail for unknown local users.
</p>
<p>
To turn off local recipient checking in the Postfix SMTP server,
specify "<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> =" (i.e. empty).
</p>
<p>
The default setting assumes that you use the default Postfix local
delivery agent for local delivery. You need to update the
<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> setting if:
</p>
<ul>
<li>You redefine the local delivery agent in <a href="master.5.html">master.cf</a>.
<li>You redefine the "<a href="postconf.5.html#local_transport">local_transport</a>" setting in <a href="postconf.5.html">main.cf</a>.
<li>You use the "<a href="postconf.5.html#luser_relay">luser_relay</a>", "<a href="postconf.5.html#mailbox_transport">mailbox_transport</a>", or "<a href="postconf.5.html#fallback_transport">fallback_transport</a>"
feature of the Postfix <a href="local.8.html">local(8)</a> delivery agent.
</ul>
<p>
Details are described in the <a href="LOCAL_RECIPIENT_README.html">LOCAL_RECIPIENT_README</a> file.
</p>
<p>
Beware: if the Postfix SMTP server runs chrooted, you need to access
the passwd file via the <a href="proxymap.8.html">proxymap(8)</a> service, in order to overcome
chroot access restrictions. The alternative, maintaining a copy of
the system password file in the chroot jail is not practical.
</p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> =
</pre>
</DD>
<DT><b><a name="local_transport">local_transport</a>
(default: <a href="local.8.html">local</a>:$<a href="postconf.5.html#myhostname">myhostname</a>)</b></DT><DD>
<p> The default mail delivery transport and next-hop destination
for final delivery to domains listed with <a href="postconf.5.html#mydestination">mydestination</a>, and for
[ipaddress] destinations that match $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>.
This information can be overruled with the <a href="transport.5.html">transport(5)</a> table. </p>
<p>
By default, local mail is delivered to the transport called "local",
which is just the name of a service that is defined the <a href="master.5.html">master.cf</a> file.
</p>
<p>
Specify a string of the form <i>transport:nexthop</i>, where <i>transport</i>
is the name of a mail delivery transport defined in <a href="master.5.html">master.cf</a>.
The <i>:nexthop</i> destination is optional; its syntax is documented
in the manual page of the corresponding delivery agent.
</p>
<p>
Beware: if you override the default local delivery agent then you
need to review the <a href="LOCAL_RECIPIENT_README.html">LOCAL_RECIPIENT_README</a> document, otherwise the
SMTP server may reject mail for local recipients.
</p>
</DD>
<DT><b><a name="luser_relay">luser_relay</a>
(default: empty)</b></DT><DD>
<p>
Optional catch-all destination for unknown <a href="local.8.html">local(8)</a> recipients.
By default, mail for unknown recipients in domains that match
$<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a> is returned
as undeliverable.
</p>
<p>
The following $name expansions are done on <a href="postconf.5.html#luser_relay">luser_relay</a>:
</p>
<dl>
<dt><b>$domain</b></dt>
<dd>The recipient domain. </dd>
<dt><b>$extension</b></dt>
<dd>The recipient address extension. </dd>
<dt><b>$home</b></dt>
<dd>The recipient's home directory. </dd>
<dt><b>$local</b></dt>
<dd>The entire recipient address localpart. </dd>
<dt><b>$recipient</b></dt>
<dd>The full recipient address. </dd>
<dt><b>$<a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a></b></dt>
<dd>The address extension delimiter that was found in the recipient
address (Postfix 2.11 and later), or the system-wide recipient
address extension delimiter (Postfix 2.10 and earlier). </dd>
<dt><b>$shell</b></dt>
<dd>The recipient's login shell. </dd>
<dt><b>$user</b></dt>
<dd>The recipient username. </dd>
<dt><b>${name?value}</b></dt>
<dd>Expands to <i>value</i> when <i>$name</i> has a non-empty value. </dd>
<dt><b>${name:value}</b></dt>
<dd>Expands to <i>value</i> when <i>$name</i> has an empty value. </dd>
</dl>
<p>
Instead of $name you can also specify ${name} or $(name).
</p>
<p>
Note: <a href="postconf.5.html#luser_relay">luser_relay</a> works only for the Postfix <a href="local.8.html">local(8)</a> delivery agent.
</p>
<p>
Note: if you use this feature for accounts not in the UNIX password
file, then you must specify "<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> =" (i.e. empty)
in the <a href="postconf.5.html">main.cf</a> file, otherwise the Postfix SMTP server will reject mail
for non-UNIX accounts with "User unknown in local recipient table".
</p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#luser_relay">luser_relay</a> = $user@other.host
<a href="postconf.5.html#luser_relay">luser_relay</a> = $local@other.host
<a href="postconf.5.html#luser_relay">luser_relay</a> = admin+$local
</pre>
</DD>
<DT><b><a name="mail_name">mail_name</a>
(default: Postfix)</b></DT><DD>
<p>
The mail system name that is displayed in Received: headers, in
the SMTP greeting banner, and in bounced mail.
</p>
</DD>
<DT><b><a name="mail_owner">mail_owner</a>
(default: postfix)</b></DT><DD>
<p>
The UNIX system account that owns the Postfix queue and most Postfix
daemon processes. Specify the name of an unprivileged user account
that does not share a user or group ID with other accounts, and that
owns no other files
or processes on the system. In particular, don't specify nobody
or daemon. PLEASE USE A DEDICATED USER ID AND GROUP ID.
</p>
<p>
When this parameter value is changed you need to re-run "<b>postfix
set-permissions</b>" (with Postfix version 2.0 and earlier:
"<b>/etc/postfix/post-install set-permissions</b>".
</p>
</DD>
<DT><b><a name="mail_release_date">mail_release_date</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
The Postfix release date, in "YYYYMMDD" format.
</p>
</DD>
<DT><b><a name="mail_spool_directory">mail_spool_directory</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
The directory where <a href="local.8.html">local(8)</a> UNIX-style mailboxes are kept. The
default setting depends on the system type. Specify a name ending
in / for maildir-style delivery.
</p>
<p>
Note: maildir delivery is done with the privileges of the recipient.
If you use the <a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a> setting for maildir style
delivery, then you must create the top-level maildir directory in
advance. Postfix will not create it.
</p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a> = /var/mail
<a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a> = /var/spool/mail
</pre>
</DD>
<DT><b><a name="mail_version">mail_version</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
The version of the mail system. Stable releases are named
<i>major</i>.<i>minor</i>.<i>patchlevel</i>. Experimental releases
also include the release date. The version string can be used in,
for example, the SMTP greeting banner.
</p>
</DD>
<DT><b><a name="mailbox_command">mailbox_command</a>
(default: empty)</b></DT><DD>
<p>
Optional external command that the <a href="local.8.html">local(8)</a> delivery agent should
use for mailbox delivery. The command is run with the user ID and
the primary group ID privileges of the recipient. Exception:
command delivery for root executes with $<a href="postconf.5.html#default_privs">default_privs</a> privileges.
This is not a problem, because 1) mail for root should always be
aliased to a real user and 2) don't log in as root, use "su" instead.
</p>
<p>
The following environment variables are exported to the command:
</p>
<dl>
<dt><b>CLIENT_ADDRESS</b></dt>
<dd>Remote client network address. Available in Postfix version 2.2 and
later. </dd>
<dt><b>CLIENT_HELO</b></dt>
<dd>Remote client EHLO command parameter. Available in Postfix version 2.2
and later.</dd>
<dt><b>CLIENT_HOSTNAME</b></dt>
<dd>Remote client hostname. Available in Postfix version 2.2 and later.
</dd>
<dt><b>CLIENT_PROTOCOL</b></dt>
<dd>Remote client protocol. Available in Postfix version 2.2 and later.
</dd>
<dt><b>DOMAIN</b></dt>
<dd>The domain part of the recipient address. </dd>
<dt><b>EXTENSION</b></dt>
<dd>The optional address extension. </dd>
<dt><b>HOME</b></dt>
<dd>The recipient home directory. </dd>
<dt><b>LOCAL</b></dt>
<dd>The recipient address localpart. </dd>
<dt><b>LOGNAME</b></dt>
<dd>The recipient's username. </dd>
<dt><b>ORIGINAL_RECIPIENT</b></dt>
<dd>The entire recipient address, before any address rewriting or
aliasing. </dd>
<dt><b>RECIPIENT</b></dt>
<dd>The full recipient address. </dd>
<dt><b>SASL_METHOD</b></dt>
<dd>SASL authentication method specified in the remote client AUTH
command. Available in Postfix version 2.2 and later. </dd>
<dt><b>SASL_SENDER</b></dt>
<dd>SASL sender address specified in the remote client MAIL FROM
command. Available in Postfix version 2.2 and later. </dd>
<dt><b>SASL_USER</b></dt>
<dd>SASL username specified in the remote client AUTH command.
Available in Postfix version 2.2 and later. </dd>
<dt><b>SENDER</b></dt>
<dd>The full sender address. </dd>
<dt><b>SHELL</b></dt>
<dd>The recipient's login shell. </dd>
<dt><b>USER</b></dt>
<dd>The recipient username. </dd>
</dl>
<p>
Unlike other Postfix configuration parameters, the <a href="postconf.5.html#mailbox_command">mailbox_command</a>
parameter is not subjected to $name substitutions. This is to make
it easier to specify shell syntax (see example below).
</p>
<p>
If you can, avoid shell meta characters because they will force
Postfix to run an expensive shell process. If you're delivering
via Procmail then running a shell won't make a noticeable difference
in the total cost.
</p>
<p>
Note: if you use the <a href="postconf.5.html#mailbox_command">mailbox_command</a> feature to deliver mail
system-wide, you must set up an alias that forwards mail for root
to a real user.
</p>
<p> The precedence of <a href="local.8.html">local(8)</a> delivery features from high to low
is: aliases, .forward files, <a href="postconf.5.html#mailbox_transport_maps">mailbox_transport_maps</a>, <a href="postconf.5.html#mailbox_transport">mailbox_transport</a>,
<a href="postconf.5.html#mailbox_command_maps">mailbox_command_maps</a>, <a href="postconf.5.html#mailbox_command">mailbox_command</a>, <a href="postconf.5.html#home_mailbox">home_mailbox</a>, <a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a>,
<a href="postconf.5.html#fallback_transport_maps">fallback_transport_maps</a>, <a href="postconf.5.html#fallback_transport">fallback_transport</a> and <a href="postconf.5.html#luser_relay">luser_relay</a>. </p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#mailbox_command">mailbox_command</a> = /some/where/procmail
<a href="postconf.5.html#mailbox_command">mailbox_command</a> = /some/where/procmail -a "$EXTENSION"
<a href="postconf.5.html#mailbox_command">mailbox_command</a> = /some/where/maildrop -d "$USER"
-f "$SENDER" "$EXTENSION"
</pre>
</DD>
<DT><b><a name="mailbox_command_maps">mailbox_command_maps</a>
(default: empty)</b></DT><DD>
<p>
Optional lookup tables with per-recipient external commands to use
for <a href="local.8.html">local(8)</a> mailbox delivery. Behavior is as with <a href="postconf.5.html#mailbox_command">mailbox_command</a>.
</p>
<p> The precedence of <a href="local.8.html">local(8)</a> delivery features from high to low
is: aliases, .forward files, <a href="postconf.5.html#mailbox_transport_maps">mailbox_transport_maps</a>, <a href="postconf.5.html#mailbox_transport">mailbox_transport</a>,
<a href="postconf.5.html#mailbox_command_maps">mailbox_command_maps</a>, <a href="postconf.5.html#mailbox_command">mailbox_command</a>, <a href="postconf.5.html#home_mailbox">home_mailbox</a>, <a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a>,
<a href="postconf.5.html#fallback_transport_maps">fallback_transport_maps</a>, <a href="postconf.5.html#fallback_transport">fallback_transport</a> and <a href="postconf.5.html#luser_relay">luser_relay</a>. </p>
<p>
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found.
</p>
</DD>
<DT><b><a name="mailbox_delivery_lock">mailbox_delivery_lock</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
How to lock a UNIX-style <a href="local.8.html">local(8)</a> mailbox before attempting delivery.
For a list of available file locking methods, use the "<b>postconf
-l</b>" command.
</p>
<p>
This setting is ignored with <b>maildir</b> style delivery,
because such deliveries are safe without explicit locks.
</p>
<p>
Note: The <b>dotlock</b> method requires that the recipient UID or
GID has write access to the parent directory of the mailbox file.
</p>
<p>
Note: the default setting of this parameter is system dependent.
</p>
</DD>
<DT><b><a name="mailbox_size_limit">mailbox_size_limit</a>
(default: 51200000)</b></DT><DD>
<p> The maximal size of any <a href="local.8.html">local(8)</a> individual mailbox or maildir
file, or zero (no limit). In fact, this limits the size of any
file that is written to upon local delivery, including files written
by external commands that are executed by the <a href="local.8.html">local(8)</a> delivery
agent. </p>
<p>
This limit must not be smaller than the message size limit.
</p>
</DD>
<DT><b><a name="mailbox_transport">mailbox_transport</a>
(default: empty)</b></DT><DD>
<p>
Optional message delivery transport that the <a href="local.8.html">local(8)</a> delivery
agent should use for mailbox delivery to all local recipients,
whether or not they are found in the UNIX passwd database.
</p>
<p> The precedence of <a href="local.8.html">local(8)</a> delivery features from high to low
is: aliases, .forward files, <a href="postconf.5.html#mailbox_transport_maps">mailbox_transport_maps</a>, <a href="postconf.5.html#mailbox_transport">mailbox_transport</a>,
<a href="postconf.5.html#mailbox_command_maps">mailbox_command_maps</a>, <a href="postconf.5.html#mailbox_command">mailbox_command</a>, <a href="postconf.5.html#home_mailbox">home_mailbox</a>, <a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a>,
<a href="postconf.5.html#fallback_transport_maps">fallback_transport_maps</a>, <a href="postconf.5.html#fallback_transport">fallback_transport</a> and <a href="postconf.5.html#luser_relay">luser_relay</a>. </p>
</DD>
<DT><b><a name="mailbox_transport_maps">mailbox_transport_maps</a>
(default: empty)</b></DT><DD>
<p> Optional lookup tables with per-recipient message delivery
transports to use for <a href="local.8.html">local(8)</a> mailbox delivery, whether or not the
recipients are found in the UNIX passwd database. </p>
<p> The precedence of <a href="local.8.html">local(8)</a> delivery features from high to low
is: aliases, .forward files, <a href="postconf.5.html#mailbox_transport_maps">mailbox_transport_maps</a>, <a href="postconf.5.html#mailbox_transport">mailbox_transport</a>,
<a href="postconf.5.html#mailbox_command_maps">mailbox_command_maps</a>, <a href="postconf.5.html#mailbox_command">mailbox_command</a>, <a href="postconf.5.html#home_mailbox">home_mailbox</a>, <a href="postconf.5.html#mail_spool_directory">mail_spool_directory</a>,
<a href="postconf.5.html#fallback_transport_maps">fallback_transport_maps</a>, <a href="postconf.5.html#fallback_transport">fallback_transport</a> and <a href="postconf.5.html#luser_relay">luser_relay</a>. </p>
<p>
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found.
</p>
<p> For safety reasons, this feature does not allow $number
substitutions in regular expression maps. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="mailq_path">mailq_path</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
Sendmail compatibility feature that specifies where the Postfix
<a href="mailq.1.html">mailq(1)</a> command is installed. This command can be used to
list the Postfix mail queue.
</p>
</DD>
<DT><b><a name="manpage_directory">manpage_directory</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
Where the Postfix manual pages are installed.
</p>
</DD>
<DT><b><a name="maps_rbl_domains">maps_rbl_domains</a>
(default: empty)</b></DT><DD>
<p>
Obsolete feature: use the <a href="postconf.5.html#reject_rbl_client">reject_rbl_client</a> feature instead.
</p>
</DD>
<DT><b><a name="maps_rbl_reject_code">maps_rbl_reject_code</a>
(default: 554)</b></DT><DD>
<p>
The numerical Postfix SMTP server response code when a remote SMTP
client request is blocked by the <a href="postconf.5.html#reject_rbl_client">reject_rbl_client</a>, <a href="postconf.5.html#reject_rhsbl_client">reject_rhsbl_client</a>,
<a href="postconf.5.html#reject_rhsbl_reverse_client">reject_rhsbl_reverse_client</a>, <a href="postconf.5.html#reject_rhsbl_sender">reject_rhsbl_sender</a> or
<a href="postconf.5.html#reject_rhsbl_recipient">reject_rhsbl_recipient</a> restriction.
</p>
<p>
Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc5321">RFC 5321</a>.
</p>
</DD>
<DT><b><a name="masquerade_classes">masquerade_classes</a>
(default: envelope_sender, header_sender, header_recipient)</b></DT><DD>
<p>
What addresses are subject to address masquerading.
</p>
<p>
By default, address masquerading is limited to envelope sender
addresses, and to header sender and header recipient addresses.
This allows you to use address masquerading on a mail gateway while
still being able to forward mail to users on individual machines.
</p>
<p>
Specify zero or more of: envelope_sender, envelope_recipient,
header_sender, header_recipient
</p>
</DD>
<DT><b><a name="masquerade_domains">masquerade_domains</a>
(default: empty)</b></DT><DD>
<p>
Optional list of domains whose subdomain structure will be stripped
off in email addresses.
</p>
<p>
The list is processed left to right, and processing stops at the
first match. Thus,
</p>
<blockquote>
<pre>
<a href="postconf.5.html#masquerade_domains">masquerade_domains</a> = foo.example.com example.com
</pre>
</blockquote>
<p>
strips "user@any.thing.foo.example.com" to "user@foo.example.com",
but strips "user@any.thing.else.example.com" to "user@example.com".
</p>
<p>
A domain name prefixed with ! means do not masquerade this domain
or its subdomains. Thus,
</p>
<blockquote>
<pre>
<a href="postconf.5.html#masquerade_domains">masquerade_domains</a> = !foo.example.com example.com
</pre>
</blockquote>
<p>
does not change "user@any.thing.foo.example.com" or "user@foo.example.com",
but strips "user@any.thing.else.example.com" to "user@example.com".
</p>
<p> Note: with Postfix version 2.2, message header address masquerading
happens only when message header address rewriting is enabled: </p>
<ul>
<li> The message is received with the Postfix <a href="sendmail.1.html">sendmail(1)</a> command,
<li> The message is received from a network client that matches
$<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a>,
<li> The message is received from the network, and the
<a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> parameter specifies a non-empty value.
</ul>
<p> To get the behavior before Postfix version 2.2, specify
"<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = <a href="DATABASE_README.html#types">static</a>:all". </p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#masquerade_domains">masquerade_domains</a> = $<a href="postconf.5.html#mydomain">mydomain</a>
</pre>
</DD>
<DT><b><a name="masquerade_exceptions">masquerade_exceptions</a>
(default: empty)</b></DT><DD>
<p>
Optional list of user names that are not subjected to address
masquerading, even when their address matches $<a href="postconf.5.html#masquerade_domains">masquerade_domains</a>.
</p>
<p>
By default, address masquerading makes no exceptions.
</p>
<p>
Specify a list of user names, "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns,
separated by commas and/or whitespace. The list is matched left to
right, and the search stops on the first match. A "/file/name"
pattern is replaced
by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table is matched when a name
matches a lookup key (the lookup result is ignored). Continue long
lines by starting the next line with whitespace. Specify "!pattern"
to exclude a name from the list. The form "!/file/name" is supported
only in Postfix version 2.4 and later. </p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#masquerade_exceptions">masquerade_exceptions</a> = root, mailer-daemon
<a href="postconf.5.html#masquerade_exceptions">masquerade_exceptions</a> = root
</pre>
</DD>
<DT><b><a name="master_service_disable">master_service_disable</a>
(default: empty)</b></DT><DD>
<p> Selectively disable <a href="master.8.html">master(8)</a> listener ports by service type
or by service name and type. Specify a list of service types
("inet", "unix", "fifo", or "pass") or "name/type" tuples, where
"name" is the first field of a <a href="master.5.html">master.cf</a> entry and "type" is a
service type. As with other Postfix matchlists, a search stops at
the first match. Specify "!pattern" to exclude a service from the
list. By default, all <a href="master.8.html">master(8)</a> listener ports are enabled. </p>
<p> Note: this feature does not support "/file/name" or "<a href="DATABASE_README.html">type:table</a>"
patterns, nor does it support wildcards such as "*" or "all". This
is intentional. </p>
<p> Examples: </p>
<pre>
# With Postfix 2.6..2.10 use '.' instead of '/'.
# Turn on all <a href="master.8.html">master(8)</a> listener ports (the default).
<a href="postconf.5.html#master_service_disable">master_service_disable</a> =
# Turn off only the main SMTP listener port.
<a href="postconf.5.html#master_service_disable">master_service_disable</a> = smtp/inet
# Turn off all TCP/IP listener ports.
<a href="postconf.5.html#master_service_disable">master_service_disable</a> = inet
# Turn off all TCP/IP listener ports except "foo".
<a href="postconf.5.html#master_service_disable">master_service_disable</a> = !foo/inet, inet
</pre>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="max_idle">max_idle</a>
(default: 100s)</b></DT><DD>
<p>
The maximum amount of time that an idle Postfix daemon process waits
for an incoming connection before terminating voluntarily. This
parameter
is ignored by the Postfix queue manager and by other long-lived
Postfix daemon processes.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="max_use">max_use</a>
(default: 100)</b></DT><DD>
<p>
The maximal number of incoming connections that a Postfix daemon
process will service before terminating voluntarily. This parameter
is ignored by the Postfix queue
manager and by other long-lived Postfix daemon processes.
</p>
</DD>
<DT><b><a name="maximal_backoff_time">maximal_backoff_time</a>
(default: 4000s)</b></DT><DD>
<p>
The maximal time between attempts to deliver a deferred message.
</p>
<p> This parameter should be set to a value greater than or equal
to $<a href="postconf.5.html#minimal_backoff_time">minimal_backoff_time</a>. See also $<a href="postconf.5.html#queue_run_delay">queue_run_delay</a>. </p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="maximal_queue_lifetime">maximal_queue_lifetime</a>
(default: 5d)</b></DT><DD>
<p>
Consider a message as undeliverable, when delivery fails with a
temporary error, and the time in the queue has reached the
<a href="postconf.5.html#maximal_queue_lifetime">maximal_queue_lifetime</a> limit.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is d (days).
</p>
<p>
Specify 0 when mail delivery should be tried only once.
</p>
</DD>
<DT><b><a name="message_drop_headers">message_drop_headers</a>
(default: bcc, content-length, resent-bcc, return-path)</b></DT><DD>
<p> Names of message headers that the <a href="cleanup.8.html">cleanup(8)</a> daemon will remove
after applying <a href="header_checks.5.html">header_checks(5)</a> and before invoking Milter applications.
The default setting is compatible with Postfix < 3.0. </p>
<p> Specify a list of header names, separated by comma or space.
Names are matched in a case-insensitive manner. The list of supported
header names is limited only by available memory. </p>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="message_reject_characters">message_reject_characters</a>
(default: empty)</b></DT><DD>
<p> The set of characters that Postfix will reject in message
content. The usual C-like escape sequences are recognized: <tt>\a
\b \f \n \r \t \v \<i>ddd</i></tt> (up to three octal digits) and
<tt>\\</tt>. </p>
<p> Note 1: this feature does not recognize text that requires MIME
decoding. It inspects raw message content, just like <a href="postconf.5.html#header_checks">header_checks</a>
and <a href="postconf.5.html#body_checks">body_checks</a>. </p>
<p> Note 2: this feature is disabled with "<a href="postconf.5.html#receive_override_options">receive_override_options</a>
= <a href="postconf.5.html#no_header_body_checks">no_header_body_checks</a>". </p>
<p> Example: </p>
<pre>
<a href="postconf.5.html#message_reject_characters">message_reject_characters</a> = \0
</pre>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="message_size_limit">message_size_limit</a>
(default: 10240000)</b></DT><DD>
<p>
The maximal size in bytes of a message, including envelope information.
</p>
<p> Note: be careful when making changes. Excessively small values
will result in the loss of non-delivery notifications, when a bounce
message size exceeds the local or remote MTA's message size limit.
</p>
</DD>
<DT><b><a name="message_strip_characters">message_strip_characters</a>
(default: empty)</b></DT><DD>
<p> The set of characters that Postfix will remove from message
content. The usual C-like escape sequences are recognized: <tt>\a
\b \f \n \r \t \v \<i>ddd</i></tt> (up to three octal digits) and
<tt>\\</tt>. </p>
<p> Note 1: this feature does not recognize text that requires MIME
decoding. It inspects raw message content, just like <a href="postconf.5.html#header_checks">header_checks</a>
and <a href="postconf.5.html#body_checks">body_checks</a>. </p>
<p> Note 2: this feature is disabled with "<a href="postconf.5.html#receive_override_options">receive_override_options</a>
= <a href="postconf.5.html#no_header_body_checks">no_header_body_checks</a>". </p>
<p> Example: </p>
<pre>
<a href="postconf.5.html#message_strip_characters">message_strip_characters</a> = \0
</pre>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="meta_directory">meta_directory</a>
(default: see 'postconf -d' output)</b></DT><DD>
<p> The location of non-executable files that are shared among
multiple Postfix instances, such as postfix-files, dynamicmaps.cf,
and the multi-instance template files <a href="postconf.5.html">main.cf</a>.proto and <a href="master.5.html">master.cf</a>.proto.
This directory should contain only Postfix-related files. Typically,
the <a href="postconf.5.html#meta_directory">meta_directory</a> parameter has the same default as the <a href="postconf.5.html#config_directory">config_directory</a>
parameter (/etc/postfix or /usr/local/etc/postfix). </p>
<p> For backwards compatibility with Postfix versions 2.6..2.11,
specify "<a href="postconf.5.html#meta_directory">meta_directory</a> = $<a href="postconf.5.html#daemon_directory">daemon_directory</a>" in <a href="postconf.5.html">main.cf</a> before
installing or upgrading Postfix, or specify "<a href="postconf.5.html#meta_directory">meta_directory</a> =
/path/name" on the "make makefiles", "make install" or "make upgrade"
command line. </p>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="milter_command_timeout">milter_command_timeout</a>
(default: 30s)</b></DT><DD>
<p> The time limit for sending an SMTP command to a Milter (mail
filter) application, and for receiving the response. </p>
<p> Specify a non-zero time value (an integral value plus an optional
one-letter suffix that specifies the time unit). </p>
<p> Time units: s (seconds), m (minutes), h (hours), d (days), w
(weeks). The default time unit is s (seconds). </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="milter_connect_macros">milter_connect_macros</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> The macros that are sent to Milter (mail filter) applications
after completion of an SMTP connection. See <a href="MILTER_README.html">MILTER_README</a>
for a list of available macro names and their meanings. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="milter_connect_timeout">milter_connect_timeout</a>
(default: 30s)</b></DT><DD>
<p> The time limit for connecting to a Milter (mail filter)
application, and for negotiating protocol options. </p>
<p> Specify a non-zero time value (an integral value plus an optional
one-letter suffix that specifies the time unit). </p>
<p> Time units: s (seconds), m (minutes), h (hours), d (days), w
(weeks). The default time unit is s (seconds). </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="milter_content_timeout">milter_content_timeout</a>
(default: 300s)</b></DT><DD>
<p> The time limit for sending message content to a Milter (mail
filter) application, and for receiving the response. </p>
<p> Specify a non-zero time value (an integral value plus an optional
one-letter suffix that specifies the time unit). </p>
<p> Time units: s (seconds), m (minutes), h (hours), d (days), w
(weeks). The default time unit is s (seconds). </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="milter_data_macros">milter_data_macros</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> The macros that are sent to version 4 or higher Milter (mail
filter) applications after the SMTP DATA command. See <a href="MILTER_README.html">MILTER_README</a>
for a list of available macro names and their meanings. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="milter_default_action">milter_default_action</a>
(default: tempfail)</b></DT><DD>
<p> The default action when a Milter (mail filter) application is
unavailable or mis-configured. Specify one of the following: </p>
<dl compact>
<dt>accept</dt> <dd>Proceed as if the mail filter was not present.
</dd>
<dt>reject</dt> <dd>Reject all further commands in this session
with a permanent status code.</dd>
<dt>tempfail</dt> <dd>Reject all further commands in this session
with a temporary status code. </dd>
<dt>quarantine</dt> <dd>Like "accept", but freeze the message in
the "<a href="QSHAPE_README.html#hold_queue">hold" queue</a>. Available with Postfix 2.6 and later. </dd>
</dl>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="milter_end_of_data_macros">milter_end_of_data_macros</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> The macros that are sent to Milter (mail filter) applications
after the message end-of-data. See <a href="MILTER_README.html">MILTER_README</a> for a list of
available macro names and their meanings. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="milter_end_of_header_macros">milter_end_of_header_macros</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> The macros that are sent to Milter (mail filter) applications
after the end of the message header. See <a href="MILTER_README.html">MILTER_README</a> for a list
of available macro names and their meanings. </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="milter_header_checks">milter_header_checks</a>
(default: empty)</b></DT><DD>
<p> Optional lookup tables for content inspection of message headers
that are produced by Milter applications. See the <a href="header_checks.5.html">header_checks(5)</a>
manual page available actions. Currently, PREPEND is not implemented.
</p>
<p> The following example sends all mail that is marked as SPAM to
a spam handling machine. Note that matches are case-insensitive
by default. </p>
<pre>
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
<a href="postconf.5.html#milter_header_checks">milter_header_checks</a> = <a href="pcre_table.5.html">pcre</a>:/etc/postfix/<a href="postconf.5.html#milter_header_checks">milter_header_checks</a>
</pre>
<pre>
/etc/postfix/<a href="postconf.5.html#milter_header_checks">milter_header_checks</a>:
/^X-SPAM-FLAG:\s+YES/ FILTER mysmtp:sanitizer.example.com:25
</pre>
<p> The <a href="postconf.5.html#milter_header_checks">milter_header_checks</a> mechanism could also be used for
whitelisting. For example it could be used to skip heavy content
inspection for DKIM-signed mail from known friendly domains. </p>
<p> This feature is available in Postfix 2.7, and as an optional
patch for Postfix 2.6. </p>
</DD>
<DT><b><a name="milter_helo_macros">milter_helo_macros</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> The macros that are sent to Milter (mail filter) applications
after the SMTP HELO or EHLO command. See
<a href="MILTER_README.html">MILTER_README</a> for a list of available macro names and their meanings.
</p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="milter_macro_daemon_name">milter_macro_daemon_name</a>
(default: $<a href="postconf.5.html#myhostname">myhostname</a>)</b></DT><DD>
<p> The {daemon_name} macro value for Milter (mail filter) applications.
See <a href="MILTER_README.html">MILTER_README</a> for a list of available macro names and their
meanings. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="milter_macro_defaults">milter_macro_defaults</a>
(default: empty)</b></DT><DD>
<p> Optional list of <i>name=value</i> pairs that specify default
values for arbitrary macros that Postfix may send to Milter
applications. These defaults are used when there is no corresponding
information from the message delivery context. </p>
<p> Specify <i>name=value</i> or <i>{name}=value</i> pairs separated
by comma or whitespace. Enclose a pair in "{}" when a value contains
comma or whitespace (this form ignores whitespace after the enclosing
"{", around the "=", and before the enclosing "}"). </p>
<p> This feature is available in Postfix 3.1 and later. </p>
</DD>
<DT><b><a name="milter_macro_v">milter_macro_v</a>
(default: $<a href="postconf.5.html#mail_name">mail_name</a> $<a href="postconf.5.html#mail_version">mail_version</a>)</b></DT><DD>
<p> The {v} macro value for Milter (mail filter) applications.
See <a href="MILTER_README.html">MILTER_README</a> for a list of available macro names and their
meanings. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="milter_mail_macros">milter_mail_macros</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> The macros that are sent to Milter (mail filter) applications
after the SMTP MAIL FROM command. See <a href="MILTER_README.html">MILTER_README</a>
for a list of available macro names and their meanings. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="milter_protocol">milter_protocol</a>
(default: 6)</b></DT><DD>
<p> The mail filter protocol version and optional protocol extensions
for communication with a Milter application; prior to Postfix 2.6
the default protocol is 2. Postfix
sends this version number during the initial protocol handshake.
It should match the version number that is expected by the mail
filter application (or by its Milter library). </p>
<p>Protocol versions: </p>
<dl compact>
<dt>2</dt> <dd>Use Sendmail 8 mail filter protocol version 2 (default
with Sendmail version 8.11 .. 8.13 and Postfix version 2.3 ..
2.5).</dd>
<dt>3</dt> <dd>Use Sendmail 8 mail filter protocol version 3.</dd>
<dt>4</dt> <dd>Use Sendmail 8 mail filter protocol version 4.</dd>
<dt>6</dt> <dd>Use Sendmail 8 mail filter protocol version 6 (default
with Sendmail version 8.14 and Postfix version 2.6).</dd>
</dl>
<p>Protocol extensions: </p>
<dl compact>
<dt>no_header_reply</dt> <dd> Specify this when the Milter application
will not reply for each individual message header.</dd>
</dl>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="milter_rcpt_macros">milter_rcpt_macros</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> The macros that are sent to Milter (mail filter) applications
after the SMTP RCPT TO command. See <a href="MILTER_README.html">MILTER_README</a>
for a list of available macro names and their meanings. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="milter_unknown_command_macros">milter_unknown_command_macros</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> The macros that are sent to version 3 or higher Milter (mail
filter) applications after an unknown SMTP command. See <a href="MILTER_README.html">MILTER_README</a>
for a list of available macro names and their meanings. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="mime_boundary_length_limit">mime_boundary_length_limit</a>
(default: 2048)</b></DT><DD>
<p>
The maximal length of MIME multipart boundary strings. The MIME
processor is unable to distinguish between boundary strings that
do not differ in the first $<a href="postconf.5.html#mime_boundary_length_limit">mime_boundary_length_limit</a> characters.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="mime_header_checks">mime_header_checks</a>
(default: $<a href="postconf.5.html#header_checks">header_checks</a>)</b></DT><DD>
<p>
Optional lookup tables for content inspection of MIME related
message headers, as described in the <a href="header_checks.5.html">header_checks(5)</a> manual page.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="mime_nesting_limit">mime_nesting_limit</a>
(default: 100)</b></DT><DD>
<p>
The maximal recursion level that the MIME processor will handle.
Postfix refuses mail that is nested deeper than the specified limit.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="minimal_backoff_time">minimal_backoff_time</a>
(default: 300s)</b></DT><DD>
<p>
The minimal time between attempts to deliver a deferred message;
prior to Postfix 2.4 the default value was 1000s.
</p>
<p>
This parameter also limits the time an unreachable destination is
kept in the short-term, in-memory, destination status cache.
</p>
<p> This parameter should be set greater than or equal to
$<a href="postconf.5.html#queue_run_delay">queue_run_delay</a>. See also $<a href="postconf.5.html#maximal_backoff_time">maximal_backoff_time</a>. </p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="multi_instance_directories">multi_instance_directories</a>
(default: empty)</b></DT><DD>
<p> An optional list of non-default Postfix configuration directories;
these directories belong to additional Postfix instances that share
the Postfix executable files and documentation with the default
Postfix instance, and that are started, stopped, etc., together
with the default Postfix instance. Specify a list of pathnames
separated by comma or whitespace. </p>
<p> When $<a href="postconf.5.html#multi_instance_directories">multi_instance_directories</a> is empty, the <a href="postfix.1.html">postfix(1)</a> command
runs in single-instance mode and operates on a single Postfix
instance only. Otherwise, the <a href="postfix.1.html">postfix(1)</a> command runs in multi-instance
mode and invokes the multi-instance manager specified with the
<a href="postconf.5.html#multi_instance_wrapper">multi_instance_wrapper</a> parameter. The multi-instance manager in
turn executes <a href="postfix.1.html">postfix(1)</a> commands for the default instance and for
all Postfix instances in $<a href="postconf.5.html#multi_instance_directories">multi_instance_directories</a>. </p>
<p> Currently, this parameter setting is ignored except for the
default <a href="postconf.5.html">main.cf</a> file. </p>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="multi_instance_enable">multi_instance_enable</a>
(default: no)</b></DT><DD>
<p> Allow this Postfix instance to be started, stopped, etc., by a
multi-instance manager. By default, new instances are created in
a safe state that prevents them from being started inadvertently.
This parameter is reserved for the multi-instance manager. </p>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="multi_instance_group">multi_instance_group</a>
(default: empty)</b></DT><DD>
<p> The optional instance group name of this Postfix instance. A
group identifies closely-related Postfix instances that the
multi-instance manager can start, stop, etc., as a unit. This
parameter is reserved for the multi-instance manager. </p>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="multi_instance_name">multi_instance_name</a>
(default: empty)</b></DT><DD>
<p> The optional instance name of this Postfix instance. This name
becomes also the default value for the <a href="postconf.5.html#syslog_name">syslog_name</a> parameter. </p>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="multi_instance_wrapper">multi_instance_wrapper</a>
(default: empty)</b></DT><DD>
<p> The pathname of a multi-instance manager command that the
<a href="postfix.1.html">postfix(1)</a> command invokes when the <a href="postconf.5.html#multi_instance_directories">multi_instance_directories</a>
parameter value is non-empty. The pathname may be followed by
initial command arguments separated by whitespace; shell
metacharacters such as quotes are not supported in this context.
</p>
<p> The <a href="postfix.1.html">postfix(1)</a> command invokes the manager command with the
<a href="postfix.1.html">postfix(1)</a> non-option command arguments on the manager command line,
and with all installation configuration parameters exported into
the manager command process environment. The manager command in
turn invokes the <a href="postfix.1.html">postfix(1)</a> command for individual Postfix instances
as "postfix -c <i><a href="postconf.5.html#config_directory">config_directory</a></i> <i>command</i>". </p>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="multi_recipient_bounce_reject_code">multi_recipient_bounce_reject_code</a>
(default: 550)</b></DT><DD>
<p>
The numerical Postfix SMTP server response code when a remote SMTP
client request is blocked by the <a href="postconf.5.html#reject_multi_recipient_bounce">reject_multi_recipient_bounce</a>
restriction.
</p>
<p>
Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc5321">RFC 5321</a>.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="mydestination">mydestination</a>
(default: $<a href="postconf.5.html#myhostname">myhostname</a>, localhost.$<a href="postconf.5.html#mydomain">mydomain</a>, localhost)</b></DT><DD>
<p> The list of domains that are delivered via the $<a href="postconf.5.html#local_transport">local_transport</a>
mail delivery transport. By default this is the Postfix <a href="local.8.html">local(8)</a>
delivery agent which looks up all recipients in /etc/passwd and
/etc/aliases. The SMTP server validates recipient addresses with
$<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> and rejects non-existent recipients. See also
the <a href="ADDRESS_CLASS_README.html#local_domain_class">local domain</a> class in the <a href="ADDRESS_CLASS_README.html">ADDRESS_CLASS_README</a> file.
</p>
<p>
The default <a href="postconf.5.html#mydestination">mydestination</a> value specifies names for the local
machine only. On a mail domain gateway, you should also include
$<a href="postconf.5.html#mydomain">mydomain</a>.
</p>
<p>
The $<a href="postconf.5.html#local_transport">local_transport</a> delivery method is also selected for mail
addressed to user@[the.net.work.address] of the mail system (the
IP addresses specified with the <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> and <a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>
parameters).
</p>
<p>
Warnings:
</p>
<ul>
<li><p>Do not specify the names of virtual domains - those domains
are specified elsewhere. See <a href="VIRTUAL_README.html">VIRTUAL_README</a> for more information. </p>
<li><p>Do not specify the names of domains that this machine is
backup MX host for. See <a href="STANDARD_CONFIGURATION_README.html">STANDARD_CONFIGURATION_README</a> for how to
set up backup MX hosts. </p>
<li><p>By default, the Postfix SMTP server rejects mail for recipients
not listed with the <a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> parameter. See the
<a href="postconf.5.html">postconf(5)</a> manual for a description of the <a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a>
and <a href="postconf.5.html#unknown_local_recipient_reject_code">unknown_local_recipient_reject_code</a> parameters. </p>
</ul>
<p>
Specify a list of host or domain names, "/file/name" or "<a href="DATABASE_README.html">type:table</a>"
patterns, separated by commas and/or whitespace. A "/file/name"
pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table
is matched when a name matches a lookup key (the lookup result is
ignored). Continue long lines by starting the next line with
whitespace. </p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#mydestination">mydestination</a> = $<a href="postconf.5.html#myhostname">myhostname</a>, localhost.$<a href="postconf.5.html#mydomain">mydomain</a> $<a href="postconf.5.html#mydomain">mydomain</a>
<a href="postconf.5.html#mydestination">mydestination</a> = $<a href="postconf.5.html#myhostname">myhostname</a>, localhost.$<a href="postconf.5.html#mydomain">mydomain</a> www.$<a href="postconf.5.html#mydomain">mydomain</a>, ftp.$<a href="postconf.5.html#mydomain">mydomain</a>
</pre>
</DD>
<DT><b><a name="mydomain">mydomain</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
The internet domain name of this mail system. The default is to
use $<a href="postconf.5.html#myhostname">myhostname</a> minus the first component, or "localdomain" (Postfix
2.3 and later). $<a href="postconf.5.html#mydomain">mydomain</a> is used as
a default value for many other configuration parameters.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#mydomain">mydomain</a> = domain.tld
</pre>
</DD>
<DT><b><a name="myhostname">myhostname</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
The internet hostname of this mail system. The default is to use
the fully-qualified domain name (FQDN) from gethostname(), or to
use the non-FQDN result from gethostname() and append ".$<a href="postconf.5.html#mydomain">mydomain</a>".
$<a href="postconf.5.html#myhostname">myhostname</a> is used as a default value for many other configuration
parameters. </p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#myhostname">myhostname</a> = host.example.com
</pre>
</DD>
<DT><b><a name="mynetworks">mynetworks</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
The list of "trusted" remote SMTP clients that have more privileges than
"strangers".
</p>
<p>
In particular, "trusted" SMTP clients are allowed to relay mail
through Postfix. See the <a href="postconf.5.html#smtpd_relay_restrictions">smtpd_relay_restrictions</a> parameter
description in the <a href="postconf.5.html">postconf(5)</a> manual.
</p>
<p>
You can specify the list of "trusted" network addresses by hand
or you can let Postfix do it for you (which is the default).
See the description of the <a href="postconf.5.html#mynetworks_style">mynetworks_style</a> parameter for more
information.
</p>
<p>
If you specify the <a href="postconf.5.html#mynetworks">mynetworks</a> list by hand,
Postfix ignores the <a href="postconf.5.html#mynetworks_style">mynetworks_style</a> setting.
</p>
<p> Specify a list of network addresses or network/netmask patterns,
separated by commas and/or whitespace. Continue long lines by
starting the next line with whitespace. </p>
<p> The netmask specifies the number of bits in the network part
of a host address. You can also specify "/file/name" or "<a href="DATABASE_README.html">type:table</a>"
patterns. A "/file/name" pattern is replaced by its contents; a
"<a href="DATABASE_README.html">type:table</a>" lookup table is matched when a table entry matches a
lookup string (the lookup result is ignored). </p>
<p> The list is matched left to right, and the search stops on the
first match. Specify "!pattern" to exclude an address or network
block from the list. The form "!/file/name" is supported only
in Postfix version 2.4 and later. </p>
<p> Note 1: Pattern matching of domain names is controlled by the
or absence of "<a href="postconf.5.html#mynetworks">mynetworks</a>" in the <a href="postconf.5.html#parent_domain_matches_subdomains">parent_domain_matches_subdomains</a>
parameter value. </p>
<p> Note 2: IP version 6 address information must be specified inside
<tt>[]</tt> in the <a href="postconf.5.html#mynetworks">mynetworks</a> value, and in files specified with
"/file/name". IP version 6 addresses contain the ":" character,
and would otherwise be confused with a "<a href="DATABASE_README.html">type:table</a>" pattern. </p>
<p> Examples: </p>
<pre>
<a href="postconf.5.html#mynetworks">mynetworks</a> = 127.0.0.0/8 168.100.189.0/28
<a href="postconf.5.html#mynetworks">mynetworks</a> = !192.168.0.1, 192.168.0.0/28
<a href="postconf.5.html#mynetworks">mynetworks</a> = 127.0.0.0/8 168.100.189.0/28 [::1]/128 [2001:240:587::]/64
<a href="postconf.5.html#mynetworks">mynetworks</a> = $<a href="postconf.5.html#config_directory">config_directory</a>/mynetworks
<a href="postconf.5.html#mynetworks">mynetworks</a> = <a href="DATABASE_README.html#types">hash</a>:/etc/postfix/network_table
</pre>
</DD>
<DT><b><a name="mynetworks_style">mynetworks_style</a>
(default: Postfix ≥ 3.0: host, Postfix < 3.0: subnet)</b></DT><DD>
<p>
The method to generate the default value for the <a href="postconf.5.html#mynetworks">mynetworks</a> parameter.
This is the list of trusted networks for relay access control etc.
</p>
<ul>
<li><p>Specify "<a href="postconf.5.html#mynetworks_style">mynetworks_style</a> = host" when Postfix should
"trust" only the local machine. </p>
<li><p>Specify "<a href="postconf.5.html#mynetworks_style">mynetworks_style</a> = subnet" when Postfix
should "trust" remote SMTP clients in the same IP subnetworks as the local
machine. On Linux, this works correctly only with interfaces
specified with the "ifconfig" command. </p>
<li><p>Specify "<a href="postconf.5.html#mynetworks_style">mynetworks_style</a> = class" when Postfix should
"trust" remote SMTP clients in the same IP class A/B/C networks as the
local machine. Caution: this may cause
Postfix to "trust" your entire provider's network. Instead, specify
an explicit <a href="postconf.5.html#mynetworks">mynetworks</a> list by hand, as described with the <a href="postconf.5.html#mynetworks">mynetworks</a>
configuration parameter. </p>
</ul>
</DD>
<DT><b><a name="myorigin">myorigin</a>
(default: $<a href="postconf.5.html#myhostname">myhostname</a>)</b></DT><DD>
<p>
The domain name that locally-posted mail appears to come
from, and that locally posted mail is delivered to. The default,
$<a href="postconf.5.html#myhostname">myhostname</a>, is adequate for small sites. If you run a domain with
multiple machines, you should (1) change this to $<a href="postconf.5.html#mydomain">mydomain</a> and (2)
set up a domain-wide alias database that aliases each user to
user@that.users.mailhost.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#myorigin">myorigin</a> = $<a href="postconf.5.html#mydomain">mydomain</a>
</pre>
</DD>
<DT><b><a name="nested_header_checks">nested_header_checks</a>
(default: $<a href="postconf.5.html#header_checks">header_checks</a>)</b></DT><DD>
<p>
Optional lookup tables for content inspection of non-MIME message
headers in attached messages, as described in the <a href="header_checks.5.html">header_checks(5)</a>
manual page.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="newaliases_path">newaliases_path</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
Sendmail compatibility feature that specifies the location of the
<a href="newaliases.1.html">newaliases(1)</a> command. This command can be used to rebuild the
<a href="local.8.html">local(8)</a> <a href="aliases.5.html">aliases(5)</a> database.
</p>
</DD>
<DT><b><a name="non_fqdn_reject_code">non_fqdn_reject_code</a>
(default: 504)</b></DT><DD>
<p>
The numerical Postfix SMTP server reply code when a client request
is rejected by the <a href="postconf.5.html#reject_non_fqdn_helo_hostname">reject_non_fqdn_helo_hostname</a>, <a href="postconf.5.html#reject_non_fqdn_sender">reject_non_fqdn_sender</a>
or <a href="postconf.5.html#reject_non_fqdn_recipient">reject_non_fqdn_recipient</a> restriction.
</p>
</DD>
<DT><b><a name="non_smtpd_milters">non_smtpd_milters</a>
(default: empty)</b></DT><DD>
<p> A list of Milter (mail filter) applications for new mail that
does not arrive via the Postfix <a href="smtpd.8.html">smtpd(8)</a> server. This includes local
submission via the <a href="sendmail.1.html">sendmail(1)</a> command line, new mail that arrives
via the Postfix <a href="qmqpd.8.html">qmqpd(8)</a> server, and old mail that is re-injected
into the queue with "postsuper -r". Specify space or comma as
separator. See the <a href="MILTER_README.html">MILTER_README</a> document for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="notify_classes">notify_classes</a>
(default: resource, software)</b></DT><DD>
<p>
The list of error classes that are reported to the postmaster. The
default is to report only the most serious problems. The paranoid
may wish to turn on the policy (UCE and mail relaying) and protocol
error (broken mail software) reports.
</p>
<p> NOTE: postmaster notifications may contain confidential information
such as SASL passwords or message content. It is the system
administrator's responsibility to treat such information with care.
</p>
<p>
The error classes are:
</p>
<dl>
<dt><b>bounce</b> (also implies <b>2bounce</b>)</dt>
<dd>Send the postmaster copies of the headers of bounced mail, and
send transcripts of SMTP sessions when Postfix rejects mail. The
notification is sent to the address specified with the
<a href="postconf.5.html#bounce_notice_recipient">bounce_notice_recipient</a> configuration parameter (default: postmaster).
</dd>
<dt><b>2bounce</b></dt>
<dd>Send undeliverable bounced mail to the postmaster. The notification
is sent to the address specified with the <a href="postconf.5.html#2bounce_notice_recipient">2bounce_notice_recipient</a>
configuration parameter (default: postmaster). </dd>
<dt><b>data</b></dt>
<dd>Send the postmaster a transcript of the SMTP session with an
error because a critical data file was unavailable. The notification
is sent to the address specified with the <a href="postconf.5.html#error_notice_recipient">error_notice_recipient</a>
configuration parameter (default: postmaster). <br> This feature
is available in Postfix 2.9 and later. </dd>
<dt><b>delay</b></dt>
<dd>Send the postmaster copies of the headers of delayed mail (see
<a href="postconf.5.html#delay_warning_time">delay_warning_time</a>). The
notification is sent to the address specified with the
<a href="postconf.5.html#delay_notice_recipient">delay_notice_recipient</a> configuration parameter (default: postmaster).
</dd>
<dt><b>policy</b></dt>
<dd>Send the postmaster a transcript of the SMTP session when a
client request was rejected because of (UCE) policy. The notification
is sent to the address specified with the <a href="postconf.5.html#error_notice_recipient">error_notice_recipient</a>
configuration parameter (default: postmaster). </dd>
<dt><b>protocol</b></dt>
<dd>Send the postmaster a transcript of the SMTP session in case
of client or server protocol errors. The notification is sent to
the address specified with the <a href="postconf.5.html#error_notice_recipient">error_notice_recipient</a> configuration
parameter (default: postmaster). </dd>
<dt><b>resource</b></dt>
<dd>Inform the postmaster of mail not delivered due to resource
problems. The notification is sent to the address specified with
the <a href="postconf.5.html#error_notice_recipient">error_notice_recipient</a> configuration parameter (default:
postmaster). </dd>
<dt><b>software</b></dt>
<dd>Inform the postmaster of mail not delivered due to software
problems. The notification is sent to the address specified with
the <a href="postconf.5.html#error_notice_recipient">error_notice_recipient</a> configuration parameter (default:
postmaster). </dd>
</dl>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#notify_classes">notify_classes</a> = bounce, delay, policy, protocol, resource, software
<a href="postconf.5.html#notify_classes">notify_classes</a> = 2bounce, resource, software
</pre>
</DD>
<DT><b><a name="nullmx_reject_code">nullmx_reject_code</a>
(default: 556)</b></DT><DD>
<p> The numerical reply code when the Postfix SMTP server rejects
a sender or recipient address because its domain has a nullmx DNS
record (an MX record with an empty hostname). This is one of the
possible replies from the restrictions <a href="postconf.5.html#reject_unknown_sender_domain">reject_unknown_sender_domain</a>
and <a href="postconf.5.html#reject_unknown_recipient_domain">reject_unknown_recipient_domain</a>. </p>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="openssl_path">openssl_path</a>
(default: openssl)</b></DT><DD>
<p>
The location of the OpenSSL command line program openssl(1). This
is used by the "<b><a href="postfix-tls.1.html">postfix tls</a></b>" command to create private keys,
certificate signing requests, self-signed certificates, and to
compute public key digests for DANE TLSA records. In multi-instance
environments, this parameter is always determined from the configuration
of the default Postfix instance.
</p>
<p> Example: </p>
<blockquote>
<pre>
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
# NetBSD pkgsrc:
<a href="postconf.5.html#openssl_path">openssl_path</a> = /usr/pkg/bin/openssl
# Local build:
<a href="postconf.5.html#openssl_path">openssl_path</a> = /usr/local/bin/openssl
</pre>
</blockquote>
<p>
This feature is available in Postfix 3.1 and later.
</p>
</DD>
<DT><b><a name="owner_request_special">owner_request_special</a>
(default: yes)</b></DT><DD>
<p>
Enable special treatment for owner-<i>listname</i> entries in the
<a href="aliases.5.html">aliases(5)</a> file, and don't split owner-<i>listname</i> and
<i>listname</i>-request address localparts when the <a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a>
is set to "-". This feature is useful for mailing lists.
</p>
</DD>
<DT><b><a name="parent_domain_matches_subdomains">parent_domain_matches_subdomains</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
A list of Postfix features where the pattern "example.com" also
matches subdomains of example.com,
instead of requiring an explicit ".example.com" pattern. This is
planned backwards compatibility: eventually, all Postfix features
are expected to require explicit ".example.com" style patterns when
you really want to match subdomains.
</p>
<p> The following Postfix feature names are supported. </p>
<dl>
<dt> Postfix version 1.0 and later</dt>
<dd>
<a href="postconf.5.html#debug_peer_list">debug_peer_list</a>,
<a href="postconf.5.html#fast_flush_domains">fast_flush_domains</a>,
<a href="postconf.5.html#mynetworks">mynetworks</a>,
<a href="postconf.5.html#permit_mx_backup_networks">permit_mx_backup_networks</a>,
<a href="postconf.5.html#relay_domains">relay_domains</a>,
<a href="postconf.5.html#transport_maps">transport_maps</a>
</dd>
<dt> Postfix version 1.1 and later</dt>
<dd>
<a href="postconf.5.html#qmqpd_authorized_clients">qmqpd_authorized_clients</a>,
smtpd_access_maps,
</dd>
<dt> Postfix version 2.8 and later </dt>
<dd>
<a href="postconf.5.html#postscreen_access_list">postscreen_access_list</a>
</dd>
<dt> Postfix version 3.0 and later </dt>
<dd>
<a href="postconf.5.html#smtpd_client_event_limit_exceptions">smtpd_client_event_limit_exceptions</a>
</dd>
</dl>
</DD>
<DT><b><a name="permit_mx_backup_networks">permit_mx_backup_networks</a>
(default: empty)</b></DT><DD>
<p>
Restrict the use of the <a href="postconf.5.html#permit_mx_backup">permit_mx_backup</a> SMTP access feature to
only domains whose primary MX hosts match the listed networks.
The parameter value syntax is the same as with the <a href="postconf.5.html#mynetworks">mynetworks</a>
parameter; note, however, that the default value is empty. </p>
<p> Pattern matching of domain names is controlled by the presence
or absence of "<a href="postconf.5.html#permit_mx_backup_networks">permit_mx_backup_networks</a>" in the
<a href="postconf.5.html#parent_domain_matches_subdomains">parent_domain_matches_subdomains</a> parameter value. </p>
</DD>
<DT><b><a name="pickup_service_name">pickup_service_name</a>
(default: pickup)</b></DT><DD>
<p>
The name of the <a href="pickup.8.html">pickup(8)</a> service. This service picks up local mail
submissions from the Postfix <a href="QSHAPE_README.html#maildrop_queue">maildrop queue</a>.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="pipe_delivery_status_filter">pipe_delivery_status_filter</a>
(default: $<a href="postconf.5.html#default_delivery_status_filter">default_delivery_status_filter</a>)</b></DT><DD>
<p> Optional filter for the <a href="pipe.8.html">pipe(8)</a> delivery agent to change the
delivery status code or explanatory text of successful or unsuccessful
deliveries. See <a href="postconf.5.html#default_delivery_status_filter">default_delivery_status_filter</a> for details. </p>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="plaintext_reject_code">plaintext_reject_code</a>
(default: 450)</b></DT><DD>
<p>
The numerical Postfix SMTP server response code when a request
is rejected by the <b><a href="postconf.5.html#reject_plaintext_session">reject_plaintext_session</a></b> restriction.
</p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="postmulti_control_commands">postmulti_control_commands</a>
(default: reload flush)</b></DT><DD>
<p> The <a href="postfix.1.html">postfix(1)</a> commands that the <a href="postmulti.1.html">postmulti(1)</a> instance manager
treats as "control" commands, that operate on running instances. For
these commands, disabled instances are skipped. </p>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="postmulti_start_commands">postmulti_start_commands</a>
(default: start)</b></DT><DD>
<p> The <a href="postfix.1.html">postfix(1)</a> commands that the <a href="postmulti.1.html">postmulti(1)</a> instance manager treats
as "start" commands. For these commands, disabled instances are "checked"
rather than "started", and failure to "start" a member instance of an
instance group will abort the start-up of later instances. </p>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="postmulti_stop_commands">postmulti_stop_commands</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> The <a href="postfix.1.html">postfix(1)</a> commands that the <a href="postmulti.1.html">postmulti(1)</a> instance manager treats
as "stop" commands. For these commands, disabled instances are skipped,
and enabled instances are processed in reverse order. </p>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="postscreen_access_list">postscreen_access_list</a>
(default: <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>)</b></DT><DD>
<p> Permanent white/blacklist for remote SMTP client IP addresses.
<a href="postscreen.8.html">postscreen(8)</a> searches this list immediately after a remote SMTP
client connects. Specify a comma- or whitespace-separated list of
commands (in upper or lower case) or lookup tables. The search stops
upon the first command that fires for the client IP address. </p>
<dl>
<dt> <b> <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a> </b> </dt> <dd> Whitelist the client and
terminate the search if the client IP address matches $<a href="postconf.5.html#mynetworks">mynetworks</a>.
Do not subject the client to any before/after 220 greeting tests.
Pass the connection immediately to a Postfix SMTP server process.
<br> Pattern matching of domain names is controlled by the presence
or absence of "<a href="postconf.5.html#postscreen_access_list">postscreen_access_list</a>" in the
<a href="postconf.5.html#parent_domain_matches_subdomains">parent_domain_matches_subdomains</a> parameter value. </dd>
<dt> <b> <a href="DATABASE_README.html">type:table</a> </b> </dt> <dd> Query the specified lookup
table. Each table lookup result is an access list, except that
access lists inside a table cannot specify <a href="DATABASE_README.html">type:table</a> entries. <br>
To discourage the use of hash, btree, etc. tables, there is no
support for substring matching like <a href="smtpd.8.html">smtpd(8)</a>. Use CIDR tables
instead. </dd>
<dt> <b> permit </b> </dt> <dd> Whitelist the client and terminate
the search. Do not subject the client to any before/after 220
greeting tests. Pass the connection immediately to a Postfix SMTP
server process. </dd>
<dt> <b> reject </b> </dt> <dd> Blacklist the client and terminate
the search. Subject the client to the action configured with the
<a href="postconf.5.html#postscreen_blacklist_action">postscreen_blacklist_action</a> configuration parameter. </dd>
<dt> <b> dunno </b> </dt> <dd> All <a href="postscreen.8.html">postscreen(8)</a> access lists
implicitly have this command at the end. <br> When <b> dunno </b>
is executed inside a lookup table, return from the lookup table and
evaluate the next command. <br> When <b> dunno </b> is executed
outside a lookup table, terminate the search, and subject the client
to the configured before/after 220 greeting tests. </dd>
</dl>
<p> Example: </p>
<pre>
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
<a href="postconf.5.html#postscreen_access_list">postscreen_access_list</a> = <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>,
<a href="cidr_table.5.html">cidr</a>:/etc/postfix/postscreen_access.cidr
<a href="postconf.5.html#postscreen_blacklist_action">postscreen_blacklist_action</a> = enforce
</pre>
<pre>
/etc/postfix/postscreen_access.<a href="cidr_table.5.html">cidr</a>:
# Rules are evaluated in the order as specified.
# Blacklist 192.168.* except 192.168.0.1.
192.168.0.1 dunno
192.168.0.0/16 reject
</pre>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_bare_newline_action">postscreen_bare_newline_action</a>
(default: ignore)</b></DT><DD>
<p> The action that <a href="postscreen.8.html">postscreen(8)</a> takes when a remote SMTP client sends
a bare newline character, that is, a newline not preceded by carriage
return. Specify one of the following: </p>
<dl>
<dt> <b>ignore</b> </dt>
<dd> Ignore the failure of this test. Allow other tests to complete.
Do <i>not</i> repeat this test before some the result from some
other test expires.
This option is useful for testing and collecting statistics
without blocking mail permanently. </dd>
<dt> <b>enforce</b> </dt>
<dd> Allow other tests to complete. Reject attempts to deliver mail
with a 550 SMTP reply, and log the helo/sender/recipient information.
Repeat this test the next time the client connects. </dd>
<dt> <b>drop</b> </dt>
<dd> Drop the connection immediately with a 521 SMTP reply. Repeat
this test the next time the client connects. </dd>
</dl>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_bare_newline_enable">postscreen_bare_newline_enable</a>
(default: no)</b></DT><DD>
<p> Enable "bare newline" SMTP protocol tests in the <a href="postscreen.8.html">postscreen(8)</a>
server. These tests are expensive: a remote SMTP client must
disconnect after
it passes the test, before it can talk to a real Postfix SMTP server.
</p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_bare_newline_ttl">postscreen_bare_newline_ttl</a>
(default: 30d)</b></DT><DD>
<p> The amount of time that <a href="postscreen.8.html">postscreen(8)</a> will use the result from
a successful "bare newline" SMTP protocol test. During this
time, the client IP address is excluded from this test. The default
is long because a remote SMTP client must disconnect after it passes
the test,
before it can talk to a real Postfix SMTP server. </p>
<p> Specify a non-zero time value (an integral value plus an optional
one-letter suffix that specifies the time unit). Time units: s
(seconds), m (minutes), h (hours), d (days), w (weeks). </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_blacklist_action">postscreen_blacklist_action</a>
(default: ignore)</b></DT><DD>
<p> The action that <a href="postscreen.8.html">postscreen(8)</a> takes when a remote SMTP client is
permanently blacklisted with the <a href="postconf.5.html#postscreen_access_list">postscreen_access_list</a> parameter.
Specify one of the following: </p>
<dl>
<dt> <b>ignore</b> (default) </dt>
<dd> Ignore this result. Allow other tests to complete. Repeat
this test the next time the client connects.
This option is useful for testing and collecting statistics
without blocking mail. </dd>
<dt> <b>enforce</b> </dt>
<dd> Allow other tests to complete. Reject attempts to deliver mail
with a 550 SMTP reply, and log the helo/sender/recipient information.
Repeat this test the next time the client connects. </dd>
<dt> <b>drop</b> </dt>
<dd> Drop the connection immediately with a 521 SMTP reply. Repeat
this test the next time the client connects. </dd>
</dl>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_cache_cleanup_interval">postscreen_cache_cleanup_interval</a>
(default: 12h)</b></DT><DD>
<p> The amount of time between <a href="postscreen.8.html">postscreen(8)</a> cache cleanup runs.
Cache cleanup increases the load on the cache database and should
therefore not be run frequently. This feature requires that the
cache database supports the "delete" and "sequence" operators.
Specify a zero interval to disable cache cleanup. </p>
<p> After each cache cleanup run, the <a href="postscreen.8.html">postscreen(8)</a> daemon logs the
number of entries that were retained and dropped. A cleanup run is
logged as "partial" when the daemon terminates early after "<b>postfix
reload</b>", "<b>postfix stop</b>", or no requests for $<a href="postconf.5.html#max_idle">max_idle</a>
seconds. </p>
<p> Time units: s (seconds), m (minutes), h (hours), d (days), w
(weeks). </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_cache_map">postscreen_cache_map</a>
(default: <a href="DATABASE_README.html#types">btree</a>:$<a href="postconf.5.html#data_directory">data_directory</a>/postscreen_cache)</b></DT><DD>
<p> Persistent storage for the <a href="postscreen.8.html">postscreen(8)</a> server decisions. </p>
<p> To share a <a href="postscreen.8.html">postscreen(8)</a> cache between multiple <a href="postscreen.8.html">postscreen(8)</a>
instances, use "<a href="postconf.5.html#postscreen_cache_map">postscreen_cache_map</a> = <a href="proxymap.8.html">proxy</a>:<a href="DATABASE_README.html#types">btree</a>:/path/to/file".
This requires Postfix version 2.9 or later; earlier <a href="proxymap.8.html">proxymap(8)</a>
implementations don't support cache cleanup. For an alternative
approach see the <a href="memcache_table.5.html">memcache_table(5)</a> manpage. </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_cache_retention_time">postscreen_cache_retention_time</a>
(default: 7d)</b></DT><DD>
<p> The amount of time that <a href="postscreen.8.html">postscreen(8)</a> will cache an expired
temporary whitelist entry before it is removed. This prevents clients
from being logged as "NEW" just because their cache entry expired
an hour ago. It also prevents the cache from filling up with clients
that passed some deep protocol test once and never came back. </p>
<p> Time units: s (seconds), m (minutes), h (hours), d (days), w
(weeks). </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_client_connection_count_limit">postscreen_client_connection_count_limit</a>
(default: $<a href="postconf.5.html#smtpd_client_connection_count_limit">smtpd_client_connection_count_limit</a>)</b></DT><DD>
<p> How many simultaneous connections any remote SMTP client is
allowed to have
with the <a href="postscreen.8.html">postscreen(8)</a> daemon. By default, this limit is the same
as with the Postfix SMTP server. Note that the triage process can
take several seconds, with the time spent in <a href="postconf.5.html#postscreen_greet_wait">postscreen_greet_wait</a>
delay, and with the time spent talking to the <a href="postscreen.8.html">postscreen(8)</a> built-in
dummy SMTP protocol engine. </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_command_count_limit">postscreen_command_count_limit</a>
(default: 20)</b></DT><DD>
<p> The limit on the total number of commands per SMTP session for
<a href="postscreen.8.html">postscreen(8)</a>'s built-in SMTP protocol engine. This SMTP engine
defers or rejects all attempts to deliver mail, therefore there is
no need to enforce separate limits on the number of junk commands
and error commands. </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_command_filter">postscreen_command_filter</a>
(default: $<a href="postconf.5.html#smtpd_command_filter">smtpd_command_filter</a>)</b></DT><DD>
<p> A mechanism to transform commands from remote SMTP clients.
See <a href="postconf.5.html#smtpd_command_filter">smtpd_command_filter</a> for further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="postscreen_command_time_limit">postscreen_command_time_limit</a>
(default: normal: 300s, overload: 10s)</b></DT><DD>
<p> The time limit to read an entire command line with <a href="postscreen.8.html">postscreen(8)</a>'s
built-in SMTP protocol engine. </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_disable_vrfy_command">postscreen_disable_vrfy_command</a>
(default: $<a href="postconf.5.html#disable_vrfy_command">disable_vrfy_command</a>)</b></DT><DD>
<p> Disable the SMTP VRFY command in the <a href="postscreen.8.html">postscreen(8)</a> daemon. See
<a href="postconf.5.html#disable_vrfy_command">disable_vrfy_command</a> for details. </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_discard_ehlo_keyword_address_maps">postscreen_discard_ehlo_keyword_address_maps</a>
(default: $<a href="postconf.5.html#smtpd_discard_ehlo_keyword_address_maps">smtpd_discard_ehlo_keyword_address_maps</a>)</b></DT><DD>
<p> Lookup tables, indexed by the remote SMTP client address, with
case insensitive lists of EHLO keywords (pipelining, starttls, auth,
etc.) that the <a href="postscreen.8.html">postscreen(8)</a> server will not send in the EHLO response
to a remote SMTP client. See <a href="postconf.5.html#smtpd_discard_ehlo_keywords">smtpd_discard_ehlo_keywords</a> for details.
The table is not searched by hostname for robustness reasons. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="postscreen_discard_ehlo_keywords">postscreen_discard_ehlo_keywords</a>
(default: $<a href="postconf.5.html#smtpd_discard_ehlo_keywords">smtpd_discard_ehlo_keywords</a>)</b></DT><DD>
<p> A case insensitive list of EHLO keywords (pipelining, starttls,
auth, etc.) that the <a href="postscreen.8.html">postscreen(8)</a> server will not send in the EHLO
response to a remote SMTP client. See <a href="postconf.5.html#smtpd_discard_ehlo_keywords">smtpd_discard_ehlo_keywords</a>
for details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="postscreen_dnsbl_action">postscreen_dnsbl_action</a>
(default: ignore)</b></DT><DD>
<p>The action that <a href="postscreen.8.html">postscreen(8)</a> takes when a remote SMTP client's combined
DNSBL score is equal to or greater than a threshold (as defined
with the <a href="postconf.5.html#postscreen_dnsbl_sites">postscreen_dnsbl_sites</a> and <a href="postconf.5.html#postscreen_dnsbl_threshold">postscreen_dnsbl_threshold</a>
parameters). Specify one of the following: </p>
<dl>
<dt> <b>ignore</b> (default) </dt>
<dd> Ignore the failure of this test. Allow other tests to complete.
Repeat this test the next time the client connects.
This option is useful for testing and collecting statistics
without blocking mail. </dd>
<dt> <b>enforce</b> </dt>
<dd> Allow other tests to complete. Reject attempts to deliver mail
with a 550 SMTP reply, and log the helo/sender/recipient information.
Repeat this test the next time the client connects. </dd>
<dt> <b>drop</b> </dt>
<dd> Drop the connection immediately with a 521 SMTP reply. Repeat
this test the next time the client connects. </dd>
</dl>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_dnsbl_max_ttl">postscreen_dnsbl_max_ttl</a>
(default: ${<a href="postconf.5.html#postscreen_dnsbl_ttl">postscreen_dnsbl_ttl</a>?{$<a href="postconf.5.html#postscreen_dnsbl_ttl">postscreen_dnsbl_ttl</a>}:{1}}h)</b></DT><DD>
<p> The maximum amount of time that <a href="postscreen.8.html">postscreen(8)</a> will use the
result from a successful DNS-based reputation test before a
client IP address is required to pass that test again. If the DNS
reply specifies a shorter TTL value, that value will be used unless
it would be smaller than <a href="postconf.5.html#postscreen_dnsbl_min_ttl">postscreen_dnsbl_min_ttl</a>. </p>
<p> Specify a non-zero time value (an integral value plus an optional
one-letter suffix that specifies the time unit). Time units: s
(seconds), m (minutes), h (hours), d (days), w (weeks). </p>
<p> This feature is available in Postfix 3.1. The default setting
is backwards-compatible with older Postfix versions. </p>
</DD>
<DT><b><a name="postscreen_dnsbl_min_ttl">postscreen_dnsbl_min_ttl</a>
(default: 60s)</b></DT><DD>
<p> The minimum amount of time that <a href="postscreen.8.html">postscreen(8)</a> will use the
result from a successful DNS-based reputation test before a
client IP address is required to pass that test again. If the DNS
reply specifies a larger TTL value, that value will be used unless
it would be larger than <a href="postconf.5.html#postscreen_dnsbl_max_ttl">postscreen_dnsbl_max_ttl</a>. </p>
<p> Specify a non-zero time value (an integral value plus an optional
one-letter suffix that specifies the time unit). Time units: s
(seconds), m (minutes), h (hours), d (days), w (weeks). </p>
<p> This feature is available in Postfix 3.1. </p>
</DD>
<DT><b><a name="postscreen_dnsbl_reply_map">postscreen_dnsbl_reply_map</a>
(default: empty)</b></DT><DD>
<p> A mapping from actual DNSBL domain name which includes a secret
password, to the DNSBL domain name that postscreen will reply with
when it rejects mail. When no mapping is found, the actual DNSBL
domain will be used. </p>
<p> For maximal stability it is best to use a file that is read
into memory such as <a href="pcre_table.5.html">pcre</a>:, <a href="regexp_table.5.html">regexp</a>: or <a href="DATABASE_README.html#types">texthash</a>: (<a href="DATABASE_README.html#types">texthash</a>: is similar
to <a href="DATABASE_README.html#types">hash</a>:, except a) there is no need to run <a href="postmap.1.html">postmap(1)</a> before the
file can be used, and b) <a href="DATABASE_README.html#types">texthash</a>: does not detect changes after
the file is read). </p>
<p> Example: </p>
<pre>
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
<a href="postconf.5.html#postscreen_dnsbl_reply_map">postscreen_dnsbl_reply_map</a> = <a href="DATABASE_README.html#types">texthash</a>:/etc/postfix/dnsbl_reply
</pre>
<pre>
/etc/postfix/dnsbl_reply:
secret.zen.spamhaus.org zen.spamhaus.org
</pre>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_dnsbl_sites">postscreen_dnsbl_sites</a>
(default: empty)</b></DT><DD>
<p>Optional list of DNS white/blacklist domains, filters and weight
factors. When the list is non-empty, the <a href="dnsblog.8.html">dnsblog(8)</a> daemon will
query these domains with the IP addresses of remote SMTP clients,
and <a href="postscreen.8.html">postscreen(8)</a> will update an SMTP client's DNSBL score with
each non-error reply. </p>
<p> Caution: when postscreen rejects mail, it replies with the DNSBL
domain name. Use the <a href="postconf.5.html#postscreen_dnsbl_reply_map">postscreen_dnsbl_reply_map</a> feature to hide
"password" information in DNSBL domain names. </p>
<p> When a client's score is equal to or greater than the threshold
specified with <a href="postconf.5.html#postscreen_dnsbl_threshold">postscreen_dnsbl_threshold</a>, <a href="postscreen.8.html">postscreen(8)</a> can drop
the connection with the remote SMTP client. </p>
<p> Specify a list of domain=filter*weight entries, separated by
comma or whitespace. </p>
<ul>
<li> <p> When no "=filter" is specified, <a href="postscreen.8.html">postscreen(8)</a> will use any
non-error DNSBL reply. Otherwise, <a href="postscreen.8.html">postscreen(8)</a> uses only DNSBL
replies that match the filter. The filter has the form d.d.d.d,
where each d is a number, or a pattern inside [] that contains one
or more ";"-separated numbers or number..number ranges. </p>
<li> <p> When no "*weight" is specified, <a href="postscreen.8.html">postscreen(8)</a> increments
the remote SMTP client's DNSBL score by 1. Otherwise, the weight must be
an integral number, and <a href="postscreen.8.html">postscreen(8)</a> adds the specified weight to
the remote SMTP client's DNSBL score. Specify a negative number for
whitelisting. </p>
<li> <p> When one <a href="postconf.5.html#postscreen_dnsbl_sites">postscreen_dnsbl_sites</a> entry produces multiple
DNSBL responses, <a href="postscreen.8.html">postscreen(8)</a> applies the weight at most once.
</p>
</ul>
<p> Examples: </p>
<p> To use example.com as a high-confidence blocklist, and to
block mail with example.net and example.org only when both agree:
</p>
<pre>
<a href="postconf.5.html#postscreen_dnsbl_threshold">postscreen_dnsbl_threshold</a> = 2
<a href="postconf.5.html#postscreen_dnsbl_sites">postscreen_dnsbl_sites</a> = example.com*2, example.net, example.org
</pre>
<p> To filter only DNSBL replies containing 127.0.0.4: </p>
<pre>
<a href="postconf.5.html#postscreen_dnsbl_sites">postscreen_dnsbl_sites</a> = example.com=127.0.0.4
</pre>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_dnsbl_threshold">postscreen_dnsbl_threshold</a>
(default: 1)</b></DT><DD>
<p> The inclusive lower bound for blocking a remote SMTP client, based on
its combined DNSBL score as defined with the <a href="postconf.5.html#postscreen_dnsbl_sites">postscreen_dnsbl_sites</a>
parameter. </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_dnsbl_timeout">postscreen_dnsbl_timeout</a>
(default: 10s)</b></DT><DD>
<p> The time limit for DNSBL or DNSWL lookups. This is separate from
the timeouts in the <a href="dnsblog.8.html">dnsblog(8)</a> daemon which are defined by system
resolver(3) routines. </p>
<p> This feature is available in Postfix 3.0. </p>
</DD>
<DT><b><a name="postscreen_dnsbl_ttl">postscreen_dnsbl_ttl</a>
(default: 1h)</b></DT><DD>
<p> The amount of time that <a href="postscreen.8.html">postscreen(8)</a> will use the result from
a successful DNS-based reputation test before a client
IP address is required to pass that test again. </p>
<p> Specify a non-zero time value (an integral value plus an optional
one-letter suffix that specifies the time unit). Time units: s
(seconds), m (minutes), h (hours), d (days), w (weeks). </p>
<p> This feature is available in Postfix 2.8-3.0. It was
replaced by <a href="postconf.5.html#postscreen_dnsbl_max_ttl">postscreen_dnsbl_max_ttl</a> in Postfix 3.1. </p>
</DD>
<DT><b><a name="postscreen_dnsbl_whitelist_threshold">postscreen_dnsbl_whitelist_threshold</a>
(default: 0)</b></DT><DD>
<p> Allow a remote SMTP client to skip "before" and "after 220
greeting" protocol tests, based on its combined DNSBL score as
defined with the <a href="postconf.5.html#postscreen_dnsbl_sites">postscreen_dnsbl_sites</a> parameter. </p>
<p> Specify a negative value to enable this feature. When a client
passes the <a href="postconf.5.html#postscreen_dnsbl_whitelist_threshold">postscreen_dnsbl_whitelist_threshold</a> without having
failed other tests, all pending or disabled tests are flagged as
completed with a time-to-live value equal to <a href="postconf.5.html#postscreen_dnsbl_ttl">postscreen_dnsbl_ttl</a>.
When a test was already completed, its time-to-live value is updated
if it was less than <a href="postconf.5.html#postscreen_dnsbl_ttl">postscreen_dnsbl_ttl</a>. </p>
<p> This feature is available in Postfix 2.11. </p>
</DD>
<DT><b><a name="postscreen_enforce_tls">postscreen_enforce_tls</a>
(default: $<a href="postconf.5.html#smtpd_enforce_tls">smtpd_enforce_tls</a>)</b></DT><DD>
<p> Mandatory TLS: announce STARTTLS support to remote SMTP clients, and
require that clients use TLS encryption. See smtpd_postscreen_enforce_tls
for details. </p>
<p> This feature is available in Postfix 2.8 and later.
Preferably, use <a href="postconf.5.html#postscreen_tls_security_level">postscreen_tls_security_level</a> instead. </p>
</DD>
<DT><b><a name="postscreen_expansion_filter">postscreen_expansion_filter</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> List of characters that are permitted in <a href="postconf.5.html#postscreen_reject_footer">postscreen_reject_footer</a>
attribute expansions. See <a href="postconf.5.html#smtpd_expansion_filter">smtpd_expansion_filter</a> for further
details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="postscreen_forbidden_commands">postscreen_forbidden_commands</a>
(default: $<a href="postconf.5.html#smtpd_forbidden_commands">smtpd_forbidden_commands</a>)</b></DT><DD>
<p> List of commands that the <a href="postscreen.8.html">postscreen(8)</a> server considers in
violation of the SMTP protocol. See <a href="postconf.5.html#smtpd_forbidden_commands">smtpd_forbidden_commands</a> for
syntax, and <a href="postconf.5.html#postscreen_non_smtp_command_action">postscreen_non_smtp_command_action</a> for possible actions.
</p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_greet_action">postscreen_greet_action</a>
(default: ignore)</b></DT><DD>
<p>The action that <a href="postscreen.8.html">postscreen(8)</a> takes when a remote SMTP client speaks
before its turn within the time specified with the <a href="postconf.5.html#postscreen_greet_wait">postscreen_greet_wait</a>
parameter. Specify one of the following: </p>
<dl>
<dt> <b>ignore</b> (default) </dt>
<dd> Ignore the failure of this test. Allow other tests to complete.
Repeat this test the next time the client connects.
This option is useful for testing and collecting statistics
without blocking mail. </dd>
<dt> <b>enforce</b> </dt>
<dd> Allow other tests to complete. Reject attempts to deliver mail
with a 550 SMTP reply, and log the helo/sender/recipient information.
Repeat this test the next time the client connects. </dd>
<dt> <b>drop</b> </dt>
<dd> Drop the connection immediately with a 521 SMTP reply. Repeat
this test the next time the client connects. </dd>
</dl>
<p> In either case, <a href="postscreen.8.html">postscreen(8)</a> will not whitelist the remote SMTP client
IP address. </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_greet_banner">postscreen_greet_banner</a>
(default: $<a href="postconf.5.html#smtpd_banner">smtpd_banner</a>)</b></DT><DD>
<p> The <i>text</i> in the optional "220-<i>text</i>..." server
response that
<a href="postscreen.8.html">postscreen(8)</a> sends ahead of the real Postfix SMTP server's "220
text..." response, in an attempt to confuse bad SMTP clients so
that they speak before their turn (pre-greet). Specify an empty
value to disable this feature. </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_greet_ttl">postscreen_greet_ttl</a>
(default: 1d)</b></DT><DD>
<p> The amount of time that <a href="postscreen.8.html">postscreen(8)</a> will use the result from
a successful PREGREET test. During this time, the client IP address
is excluded from this test. The default is relatively short, because
a good client can immediately talk to a real Postfix SMTP server. </p>
<p> Specify a non-zero time value (an integral value plus an optional
one-letter suffix that specifies the time unit). Time units: s
(seconds), m (minutes), h (hours), d (days), w (weeks). </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_greet_wait">postscreen_greet_wait</a>
(default: normal: 6s, overload: 2s)</b></DT><DD>
<p> The amount of time that <a href="postscreen.8.html">postscreen(8)</a> will wait for an SMTP
client to send a command before its turn, and for DNS blocklist
lookup results to arrive (default: up to 2 seconds under stress,
up to 6 seconds otherwise). <p>
<p> Specify a non-zero time value (an integral value plus an optional
one-letter suffix that specifies the time unit). </p>
<p> Time units: s (seconds), m (minutes), h (hours), d (days), w
(weeks). </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_helo_required">postscreen_helo_required</a>
(default: $<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a>)</b></DT><DD>
<p> Require that a remote SMTP client sends HELO or EHLO before
commencing a MAIL transaction. </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_non_smtp_command_action">postscreen_non_smtp_command_action</a>
(default: drop)</b></DT><DD>
<p> The action that <a href="postscreen.8.html">postscreen(8)</a> takes when a remote SMTP client sends
non-SMTP commands as specified with the <a href="postconf.5.html#postscreen_forbidden_commands">postscreen_forbidden_commands</a>
parameter. Specify one of the following: </p>
<dl>
<dt> <b>ignore</b> </dt>
<dd> Ignore the failure of this test. Allow other tests to complete.
Do <i>not</i> repeat this test before some the result from some
other test expires.
This option is useful for testing and collecting statistics
without blocking mail permanently. </dd>
<dt> <b>enforce</b> </dt>
<dd> Allow other tests to complete. Reject attempts to deliver mail
with a 550 SMTP reply, and log the helo/sender/recipient information.
Repeat this test the next time the client connects. </dd>
<dt> <b>drop</b> </dt>
<dd> Drop the connection immediately with a 521 SMTP reply. Repeat
this test the next time the client connects. This action is the
same as with the Postfix SMTP server's <a href="postconf.5.html#smtpd_forbidden_commands">smtpd_forbidden_commands</a>
feature. </dd>
</dl>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_non_smtp_command_enable">postscreen_non_smtp_command_enable</a>
(default: no)</b></DT><DD>
<p> Enable "non-SMTP command" tests in the <a href="postscreen.8.html">postscreen(8)</a> server. These
tests are expensive: a client must disconnect after it passes the
test, before it can talk to a real Postfix SMTP server. </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_non_smtp_command_ttl">postscreen_non_smtp_command_ttl</a>
(default: 30d)</b></DT><DD>
<p> The amount of time that <a href="postscreen.8.html">postscreen(8)</a> will use the result from
a successful "non_smtp_command" SMTP protocol test. During this
time, the client IP address is excluded from this test. The default
is long because a client must disconnect after it passes the test,
before it can talk to a real Postfix SMTP server. </p>
<p> Specify a non-zero time value (an integral value plus an optional
one-letter suffix that specifies the time unit). Time units: s
(seconds), m (minutes), h (hours), d (days), w (weeks). </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_pipelining_action">postscreen_pipelining_action</a>
(default: enforce)</b></DT><DD>
<p> The action that <a href="postscreen.8.html">postscreen(8)</a> takes when a remote SMTP client
sends
multiple commands instead of sending one command and waiting for
the server to respond. Specify one of the following: </p>
<dl>
<dt> <b>ignore</b> </dt>
<dd> Ignore the failure of this test. Allow other tests to complete.
Do <i>not</i> repeat this test before some the result from some
other test expires.
This option is useful for testing and collecting statistics
without blocking mail permanently. </dd>
<dt> <b>enforce</b> </dt>
<dd> Allow other tests to complete. Reject attempts to deliver mail
with a 550 SMTP reply, and log the helo/sender/recipient information.
Repeat this test the next time the client connects. </dd>
<dt> <b>drop</b> </dt>
<dd> Drop the connection immediately with a 521 SMTP reply. Repeat
this test the next time the client connects. </dd>
</dl>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_pipelining_enable">postscreen_pipelining_enable</a>
(default: no)</b></DT><DD>
<p> Enable "pipelining" SMTP protocol tests in the <a href="postscreen.8.html">postscreen(8)</a>
server. These tests are expensive: a good client must disconnect
after it passes the test, before it can talk to a real Postfix SMTP
server. </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_pipelining_ttl">postscreen_pipelining_ttl</a>
(default: 30d)</b></DT><DD>
<p> The amount of time that <a href="postscreen.8.html">postscreen(8)</a> will use the result from
a successful "pipelining" SMTP protocol test. During this time, the
client IP address is excluded from this test. The default is
long because a good client must disconnect after it passes the test,
before it can talk to a real Postfix SMTP server. </p>
<p> Specify a non-zero time value (an integral value plus an optional
one-letter suffix that specifies the time unit). Time units: s
(seconds), m (minutes), h (hours), d (days), w (weeks). </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_post_queue_limit">postscreen_post_queue_limit</a>
(default: $<a href="postconf.5.html#default_process_limit">default_process_limit</a>)</b></DT><DD>
<p> The number of clients that can be waiting for service from a
real Postfix SMTP server process. When this queue is full, all
clients will
receive a 421 response. </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_pre_queue_limit">postscreen_pre_queue_limit</a>
(default: $<a href="postconf.5.html#default_process_limit">default_process_limit</a>)</b></DT><DD>
<p> The number of non-whitelisted clients that can be waiting for
a decision whether they will receive service from a real Postfix
SMTP server
process. When this queue is full, all non-whitelisted clients will
receive a 421 response. </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_reject_footer">postscreen_reject_footer</a>
(default: $<a href="postconf.5.html#smtpd_reject_footer">smtpd_reject_footer</a>)</b></DT><DD>
<p> Optional information that is appended after a 4XX or 5XX
<a href="postscreen.8.html">postscreen(8)</a> server
response. See <a href="postconf.5.html#smtpd_reject_footer">smtpd_reject_footer</a> for further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="postscreen_tls_security_level">postscreen_tls_security_level</a>
(default: $<a href="postconf.5.html#smtpd_tls_security_level">smtpd_tls_security_level</a>)</b></DT><DD>
<p> The SMTP TLS security level for the <a href="postscreen.8.html">postscreen(8)</a> server; when
a non-empty value is specified, this overrides the obsolete parameters
<a href="postconf.5.html#postscreen_use_tls">postscreen_use_tls</a> and <a href="postconf.5.html#postscreen_enforce_tls">postscreen_enforce_tls</a>. See <a href="postconf.5.html#smtpd_tls_security_level">smtpd_tls_security_level</a>
for details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="postscreen_upstream_proxy_protocol">postscreen_upstream_proxy_protocol</a>
(default: empty)</b></DT><DD>
<p> The name of the proxy protocol used by an optional before-postscreen
proxy agent. When a proxy agent is used, this protocol conveys local
and remote address and port information. Specify
"<a href="postconf.5.html#postscreen_upstream_proxy_protocol">postscreen_upstream_proxy_protocol</a> = haproxy" to enable the haproxy
protocol. <p>
<p> This feature is available in Postfix 2.10 and later. </p>
</DD>
<DT><b><a name="postscreen_upstream_proxy_timeout">postscreen_upstream_proxy_timeout</a>
(default: 5s)</b></DT><DD>
<p> The time limit for the proxy protocol specified with the
<a href="postconf.5.html#postscreen_upstream_proxy_protocol">postscreen_upstream_proxy_protocol</a> parameter. </p>
<p> This feature is available in Postfix 2.10 and later. </p>
</DD>
<DT><b><a name="postscreen_use_tls">postscreen_use_tls</a>
(default: $<a href="postconf.5.html#smtpd_use_tls">smtpd_use_tls</a>)</b></DT><DD>
<p> Opportunistic TLS: announce STARTTLS support to remote SMTP clients,
but do not require that clients use TLS encryption. </p>
<p> This feature is available in Postfix 2.8 and later.
Preferably, use <a href="postconf.5.html#postscreen_tls_security_level">postscreen_tls_security_level</a> instead. </p>
</DD>
<DT><b><a name="postscreen_watchdog_timeout">postscreen_watchdog_timeout</a>
(default: 10s)</b></DT><DD>
<p> How much time a <a href="postscreen.8.html">postscreen(8)</a> process may take to respond to
a remote SMTP client command or to perform a cache operation before it
is terminated by a built-in watchdog timer. This is a safety
mechanism that prevents <a href="postscreen.8.html">postscreen(8)</a> from becoming non-responsive
due to a bug in Postfix itself or in system software. To avoid
false alarms and unnecessary cache corruption this limit cannot be
set under 10s. </p>
<p> Specify a non-zero time value (an integral value plus an optional
one-letter suffix that specifies the time unit). Time units: s
(seconds), m (minutes), h (hours), d (days), w (weeks). </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="postscreen_whitelist_interfaces">postscreen_whitelist_interfaces</a>
(default: <a href="DATABASE_README.html#types">static</a>:all)</b></DT><DD>
<p> A list of local <a href="postscreen.8.html">postscreen(8)</a> server IP addresses where a
non-whitelisted remote SMTP client can obtain <a href="postscreen.8.html">postscreen(8)</a>'s temporary
whitelist status. This status is required before the client can
talk to a Postfix SMTP server process. By default, a client can
obtain <a href="postscreen.8.html">postscreen(8)</a>'s whitelist status on any local <a href="postscreen.8.html">postscreen(8)</a>
server IP address. </p>
<p> When <a href="postscreen.8.html">postscreen(8)</a> listens on both primary and backup MX
addresses, the <a href="postconf.5.html#postscreen_whitelist_interfaces">postscreen_whitelist_interfaces</a> parameter can be
configured to give the temporary whitelist status only when a client
connects to a primary MX address. Once a client is whitelisted it
can talk to a Postfix SMTP server on any address. Thus, clients
that connect only to backup MX addresses will never become whitelisted,
and will never be allowed to talk to a Postfix SMTP server process.
</p>
<p> Specify a list of network addresses or network/netmask patterns,
separated by commas and/or whitespace. The netmask specifies the
number of bits in the network part of a host address. Continue long
lines by starting the next line with whitespace. </p>
<p> You can also specify "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns. A
"/file/name" pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>"
lookup table is matched when a table entry matches a lookup string
(the lookup result is ignored). </p>
<p> The list is matched left to right, and the search stops on the
first match. Specify "!pattern" to exclude an address or network
block from the list. </p>
<p> Note: IP version 6 address information must be specified inside
[] in the <a href="postconf.5.html#postscreen_whitelist_interfaces">postscreen_whitelist_interfaces</a> value, and in files
specified with "/file/name". IP version 6 addresses contain the
":" character, and would otherwise be confused with a "<a href="DATABASE_README.html">type:table</a>"
pattern. </p>
<p> Example: </p>
<pre>
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
# Don't whitelist connections to the backup IP address.
<a href="postconf.5.html#postscreen_whitelist_interfaces">postscreen_whitelist_interfaces</a> = !168.100.189.8, <a href="DATABASE_README.html#types">static</a>:all
</pre>
<p> This feature is available in Postfix 2.9 and later. </p>
</DD>
<DT><b><a name="prepend_delivered_header">prepend_delivered_header</a>
(default: command, file, forward)</b></DT><DD>
<p> The message delivery contexts where the Postfix <a href="local.8.html">local(8)</a> delivery
agent prepends a Delivered-To: message header with the address
that the mail was delivered to. This information is used for mail
delivery loop detection. </p>
<p>
By default, the Postfix local delivery agent prepends a Delivered-To:
header when forwarding mail and when delivering to file (mailbox)
and command. Turning off the Delivered-To: header when forwarding
mail is not recommended.
</p>
<p>
Specify zero or more of <b>forward</b>, <b>file</b>, or <b>command</b>.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#prepend_delivered_header">prepend_delivered_header</a> = forward
</pre>
</DD>
<DT><b><a name="process_id">process_id</a>
(read-only)</b></DT><DD>
<p>
The process ID of a Postfix command or daemon process.
</p>
</DD>
<DT><b><a name="process_id_directory">process_id_directory</a>
(default: pid)</b></DT><DD>
<p>
The location of Postfix PID files relative to $<a href="postconf.5.html#queue_directory">queue_directory</a>.
This is a read-only parameter.
</p>
</DD>
<DT><b><a name="process_name">process_name</a>
(read-only)</b></DT><DD>
<p>
The process name of a Postfix command or daemon process.
</p>
</DD>
<DT><b><a name="propagate_unmatched_extensions">propagate_unmatched_extensions</a>
(default: canonical, virtual)</b></DT><DD>
<p>
What address lookup tables copy an address extension from the lookup
key to the lookup result.
</p>
<p>
For example, with a <a href="virtual.5.html">virtual(5)</a> mapping of "<i>joe@example.com =>
joe.user@example.net</i>", the address "<i>joe+foo@example.com</i>"
would rewrite to "<i>joe.user+foo@example.net</i>".
</p>
<p>
Specify zero or more of <b>canonical</b>, <b>virtual</b>, <b>alias</b>,
<b>forward</b>, <b>include</b> or <b>generic</b>. These cause
address extension
propagation with <a href="canonical.5.html">canonical(5)</a>, <a href="virtual.5.html">virtual(5)</a>, and <a href="aliases.5.html">aliases(5)</a> maps,
with <a href="local.8.html">local(8)</a> .forward and :include: file lookups, and with <a href="smtp.8.html">smtp(8)</a>
generic maps, respectively. </p>
<p>
Note: enabling this feature for types other than <b>canonical</b>
and <b>virtual</b> is likely to cause problems when mail is forwarded
to other sites, especially with mail that is sent to a mailing list
exploder address.
</p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#propagate_unmatched_extensions">propagate_unmatched_extensions</a> = canonical, virtual, alias,
forward, include
<a href="postconf.5.html#propagate_unmatched_extensions">propagate_unmatched_extensions</a> = canonical, virtual
</pre>
</DD>
<DT><b><a name="proxy_interfaces">proxy_interfaces</a>
(default: empty)</b></DT><DD>
<p>
The network interface addresses that this mail system receives mail
on by way of a proxy or network address translation unit.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
<p> You must specify your "outside" proxy/NAT addresses when your
system is a backup MX host for other domains, otherwise mail delivery
loops will happen when the primary MX host is down. </p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a> = 1.2.3.4
</pre>
</DD>
<DT><b><a name="proxy_read_maps">proxy_read_maps</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
The lookup tables that the <a href="proxymap.8.html">proxymap(8)</a> server is allowed to
access for the read-only service.
</p>
<p>
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma.
Table references that don't begin with <a href="proxymap.8.html">proxy</a>: are ignored.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="proxy_write_maps">proxy_write_maps</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> The lookup tables that the <a href="proxymap.8.html">proxymap(8)</a> server is allowed to
access for the read-write service. Postfix-owned local database
files should be stored under the Postfix-owned <a href="postconf.5.html#data_directory">data_directory</a>.
Table references that don't begin with <a href="proxymap.8.html">proxy</a>: are ignored. </p>
<p>
This feature is available in Postfix 2.5 and later.
</p>
</DD>
<DT><b><a name="proxymap_service_name">proxymap_service_name</a>
(default: proxymap)</b></DT><DD>
<p> The name of the proxymap read-only table lookup service. This
service is normally implemented by the <a href="proxymap.8.html">proxymap(8)</a> daemon. </p>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="proxywrite_service_name">proxywrite_service_name</a>
(default: proxywrite)</b></DT><DD>
<p> The name of the proxywrite read-write table lookup service.
This service is normally implemented by the <a href="proxymap.8.html">proxymap(8)</a> daemon.
</p>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="qmgr_clog_warn_time">qmgr_clog_warn_time</a>
(default: 300s)</b></DT><DD>
<p>
The minimal delay between warnings that a specific destination is
clogging up the Postfix <a href="QSHAPE_README.html#active_queue">active queue</a>. Specify 0 to disable.
</p>
<p>
This feature is enabled with the <a href="postconf.5.html#helpful_warnings">helpful_warnings</a> parameter.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="qmgr_daemon_timeout">qmgr_daemon_timeout</a>
(default: 1000s)</b></DT><DD>
<p> How much time a Postfix queue manager process may take to handle
a request before it is terminated by a built-in watchdog timer.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="qmgr_fudge_factor">qmgr_fudge_factor</a>
(default: 100)</b></DT><DD>
<p>
Obsolete feature: the percentage of delivery resources that a busy
mail system will use up for delivery of a large mailing list
message.
</p>
<p>
This feature exists only in the <a href="qmgr.8.html">oqmgr(8)</a> old queue manager. The
current queue manager solves the problem in a better way.
</p>
</DD>
<DT><b><a name="qmgr_ipc_timeout">qmgr_ipc_timeout</a>
(default: 60s)</b></DT><DD>
<p> The time limit for the queue manager to send or receive information
over an internal communication channel. The purpose is to break
out of deadlock situations. If the time limit is exceeded the
software either retries or aborts the operation. </p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="qmgr_message_active_limit">qmgr_message_active_limit</a>
(default: 20000)</b></DT><DD>
<p>
The maximal number of messages in the <a href="QSHAPE_README.html#active_queue">active queue</a>.
</p>
</DD>
<DT><b><a name="qmgr_message_recipient_limit">qmgr_message_recipient_limit</a>
(default: 20000)</b></DT><DD>
<p> The maximal number of recipients held in memory by the Postfix
queue manager, and the maximal size of the short-term,
in-memory "dead" destination status cache. </p>
</DD>
<DT><b><a name="qmgr_message_recipient_minimum">qmgr_message_recipient_minimum</a>
(default: 10)</b></DT><DD>
<p>
The minimal number of in-memory recipients for any message. This
takes priority over any other in-memory recipient limits (i.e.,
the global <a href="postconf.5.html#qmgr_message_recipient_limit">qmgr_message_recipient_limit</a> and the per transport
_recipient_limit) if necessary. The minimum value allowed for this
parameter is 1.
</p>
</DD>
<DT><b><a name="qmqpd_authorized_clients">qmqpd_authorized_clients</a>
(default: empty)</b></DT><DD>
<p>
What remote QMQP clients are allowed to connect to the Postfix QMQP
server port.
</p>
<p>
By default, no client is allowed to use the service. This is
because the QMQP server will relay mail to any destination.
</p>
<p>
Specify a list of client patterns. A list pattern specifies a host
name, a domain name, an internet address, or a network/mask pattern,
where the mask specifies the number of bits in the network part.
When a pattern specifies a file name, its contents are substituted
for the file name; when a pattern is a "<a href="DATABASE_README.html">type:table</a>" table specification,
table lookup is used instead. </p>
<p>
Patterns are separated by whitespace and/or commas. In order to
reverse the result, precede a pattern with an
exclamation point (!). The form "!/file/name" is supported only
in Postfix version 2.4 and later.
</p>
<p> Pattern matching of domain names is controlled by the presence
or absence of "<a href="postconf.5.html#qmqpd_authorized_clients">qmqpd_authorized_clients</a>" in the
<a href="postconf.5.html#parent_domain_matches_subdomains">parent_domain_matches_subdomains</a> parameter value. </p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#qmqpd_authorized_clients">qmqpd_authorized_clients</a> = !192.168.0.1, 192.168.0.0/24
</pre>
</DD>
<DT><b><a name="qmqpd_client_port_logging">qmqpd_client_port_logging</a>
(default: no)</b></DT><DD>
<p> Enable logging of the remote QMQP client port in addition to
the hostname and IP address. The logging format is "host[address]:port".
</p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="qmqpd_error_delay">qmqpd_error_delay</a>
(default: 1s)</b></DT><DD>
<p>
How long the Postfix QMQP server will pause before sending a negative
reply to the remote QMQP client. The purpose is to slow down confused
or malicious clients.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="qmqpd_timeout">qmqpd_timeout</a>
(default: 300s)</b></DT><DD>
<p>
The time limit for sending or receiving information over the network.
If a read or write operation blocks for more than $<a href="postconf.5.html#qmqpd_timeout">qmqpd_timeout</a>
seconds the Postfix QMQP server gives up and disconnects.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="queue_directory">queue_directory</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
The location of the Postfix top-level queue directory. This is the
root directory of Postfix daemon processes that run chrooted.
</p>
</DD>
<DT><b><a name="queue_file_attribute_count_limit">queue_file_attribute_count_limit</a>
(default: 100)</b></DT><DD>
<p>
The maximal number of (name=value) attributes that may be stored
in a Postfix queue file. The limit is enforced by the <a href="cleanup.8.html">cleanup(8)</a>
server.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="queue_minfree">queue_minfree</a>
(default: 0)</b></DT><DD>
<p>
The minimal amount of free space in bytes in the queue file system
that is needed to receive mail. This is currently used by the
Postfix SMTP server to decide if it will accept any mail at all.
</p>
<p>
By default, the Postfix SMTP server rejects MAIL FROM commands when
the amount of free space is less than 1.5*$<a href="postconf.5.html#message_size_limit">message_size_limit</a>
(Postfix version 2.1 and later).
To specify a higher minimum free space limit, specify a <a href="postconf.5.html#queue_minfree">queue_minfree</a>
value that is at least 1.5*$<a href="postconf.5.html#message_size_limit">message_size_limit</a>.
</p>
<p>
With Postfix versions 2.0 and earlier, a <a href="postconf.5.html#queue_minfree">queue_minfree</a> value of
zero means there is no minimum required amount of free space.
</p>
</DD>
<DT><b><a name="queue_run_delay">queue_run_delay</a>
(default: 300s)</b></DT><DD>
<p>
The time between <a href="QSHAPE_README.html#deferred_queue">deferred queue</a> scans by the queue manager;
prior to Postfix 2.4 the default value was 1000s.
</p>
<p> This parameter should be set less than or equal to
$<a href="postconf.5.html#minimal_backoff_time">minimal_backoff_time</a>. See also $<a href="postconf.5.html#maximal_backoff_time">maximal_backoff_time</a>. </p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="queue_service_name">queue_service_name</a>
(default: qmgr)</b></DT><DD>
<p>
The name of the <a href="qmgr.8.html">qmgr(8)</a> service. This service manages the Postfix
queue and schedules delivery requests.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="rbl_reply_maps">rbl_reply_maps</a>
(default: empty)</b></DT><DD>
<p>
Optional lookup tables with RBL response templates. The tables are
indexed by the RBL domain name. By default, Postfix uses the default
template as specified with the <a href="postconf.5.html#default_rbl_reply">default_rbl_reply</a> configuration
parameter. See there for a discussion of the syntax of RBL reply
templates.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="readme_directory">readme_directory</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
The location of Postfix README files that describe how to build,
configure or operate a specific Postfix subsystem or feature.
</p>
</DD>
<DT><b><a name="receive_override_options">receive_override_options</a>
(default: empty)</b></DT><DD>
<p> Enable or disable recipient validation, built-in content
filtering, or address mapping. Typically, these are specified in
<a href="master.5.html">master.cf</a> as command-line arguments for the <a href="smtpd.8.html">smtpd(8)</a>, <a href="qmqpd.8.html">qmqpd(8)</a> or
<a href="pickup.8.html">pickup(8)</a> daemons. </p>
<p> Specify zero or more of the following options. The options
override <a href="postconf.5.html">main.cf</a> settings and are either implemented by <a href="smtpd.8.html">smtpd(8)</a>,
<a href="qmqpd.8.html">qmqpd(8)</a>, or <a href="pickup.8.html">pickup(8)</a> themselves, or they are forwarded to the
cleanup server. </p>
<dl>
<dt><b><a name="no_unknown_recipient_checks">no_unknown_recipient_checks</a></b></dt>
<dd>Do not try to reject unknown recipients (SMTP server only).
This is typically specified AFTER an external content filter.
</dd>
<dt><b><a name="no_address_mappings">no_address_mappings</a></b></dt>
<dd>Disable canonical address mapping, virtual alias map expansion,
address masquerading, and automatic BCC (blind carbon-copy)
recipients. This is typically specified BEFORE an external content
filter. </dd>
<dt><b><a name="no_header_body_checks">no_header_body_checks</a></b></dt>
<dd>Disable header/body_checks. This is typically specified AFTER
an external content filter. </dd>
<dt><b><a name="no_milters">no_milters</a></b></dt>
<dd>Disable Milter (mail filter) applications. This is typically
specified AFTER an external content filter. </dd>
</dl>
<p>
Note: when the "BEFORE content filter" <a href="postconf.5.html#receive_override_options">receive_override_options</a>
setting is specified in the <a href="postconf.5.html">main.cf</a> file, specify the "AFTER content
filter" <a href="postconf.5.html#receive_override_options">receive_override_options</a> setting in <a href="master.5.html">master.cf</a> (and vice
versa).
</p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#receive_override_options">receive_override_options</a> =
<a href="postconf.5.html#no_unknown_recipient_checks">no_unknown_recipient_checks</a>, <a href="postconf.5.html#no_header_body_checks">no_header_body_checks</a>
<a href="postconf.5.html#receive_override_options">receive_override_options</a> = <a href="postconf.5.html#no_address_mappings">no_address_mappings</a>
</pre>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="recipient_bcc_maps">recipient_bcc_maps</a>
(default: empty)</b></DT><DD>
<p>
Optional BCC (blind carbon-copy) address lookup tables, indexed by
recipient address. The BCC address (multiple results are not
supported) is added when mail enters from outside of Postfix.
</p>
<p>
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found.
</p>
<p>
The table search order is as follows:
</p>
<ul>
<li> Look up the "user+extension@domain.tld" address including the
optional address extension.
<li> Look up the "user@domain.tld" address without the optional
address extension.
<li> Look up the "user+extension" address local part when the
recipient domain equals $<a href="postconf.5.html#myorigin">myorigin</a>, $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>
or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>.
<li> Look up the "user" address local part when the recipient domain
equals $<a href="postconf.5.html#myorigin">myorigin</a>, $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>.
<li> Look up the "@domain.tld" part.
</ul>
<p>
Note: with Postfix 2.3 and later the BCC address is added as if it
was specified with NOTIFY=NONE. The sender will not be notified
when the BCC address is undeliverable, as long as all down-stream
software implements <a href="http://tools.ietf.org/html/rfc3461">RFC 3461</a>.
</p>
<p>
Note: with Postfix 2.2 and earlier the sender will unconditionally
be notified when the BCC address is undeliverable.
</p>
<p> Note: automatic BCC recipients are produced only for new mail.
To avoid mailer loops, automatic BCC recipients are not generated
after Postfix forwards mail internally, or after Postfix generates
mail itself. </p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#recipient_bcc_maps">recipient_bcc_maps</a> = <a href="DATABASE_README.html#types">hash</a>:/etc/postfix/recipient_bcc
</pre>
<p>
After a change, run "<b>postmap /etc/postfix/recipient_bcc</b>".
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="recipient_canonical_classes">recipient_canonical_classes</a>
(default: envelope_recipient, header_recipient)</b></DT><DD>
<p> What addresses are subject to <a href="postconf.5.html#recipient_canonical_maps">recipient_canonical_maps</a> address
mapping. By default, <a href="postconf.5.html#recipient_canonical_maps">recipient_canonical_maps</a> address mapping is
applied to envelope recipient addresses, and to header recipient
addresses. </p>
<p> Specify one or more of: envelope_recipient, header_recipient
</p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="recipient_canonical_maps">recipient_canonical_maps</a>
(default: empty)</b></DT><DD>
<p>
Optional address mapping lookup tables for envelope and header
recipient addresses.
The table format and lookups are documented in <a href="canonical.5.html">canonical(5)</a>.
</p>
<p>
Note: $<a href="postconf.5.html#recipient_canonical_maps">recipient_canonical_maps</a> is processed before $<a href="postconf.5.html#canonical_maps">canonical_maps</a>.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#recipient_canonical_maps">recipient_canonical_maps</a> = <a href="DATABASE_README.html#types">hash</a>:/etc/postfix/recipient_canonical
</pre>
</DD>
<DT><b><a name="recipient_delimiter">recipient_delimiter</a>
(default: empty)</b></DT><DD>
<p> The set of characters that can separate a user name from its
extension (example: user+foo), or a .forward file name from its
extension (example: .forward+foo). Basically, the software tries
user+foo and .forward+foo before trying user and .forward. This
implementation recognizes one delimiter character and one extension
per email address or .forward file name. </p>
<p> When the <a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a> set contains multiple characters
(Postfix 2.11 and later), a user name or .forward file name is
separated from its extension by the first character that matches
the <a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a> set. </p>
<p> See <a href="canonical.5.html">canonical(5)</a>, <a href="local.8.html">local(8)</a>, <a href="relocated.5.html">relocated(5)</a> and <a href="virtual.5.html">virtual(5)</a> for the
effects of <a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a> on lookups in aliases, canonical,
virtual, and relocated maps, and see the <a href="postconf.5.html#propagate_unmatched_extensions">propagate_unmatched_extensions</a>
parameter for propagating an extension from one email address to
another. </p>
<p> When used in <a href="postconf.5.html#command_execution_directory">command_execution_directory</a>, <a href="postconf.5.html#forward_path">forward_path</a>, or
<a href="postconf.5.html#luser_relay">luser_relay</a>, ${<a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a>} is replaced with the actual
recipient delimiter that was found in the recipient email address
(Postfix 2.11 and later), or it is replaced with the <a href="postconf.5.html">main.cf</a>
<a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a> parameter value (Postfix 2.10 and earlier).
</p>
<p> The <a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a> is not applied to the mailer-daemon
address, the postmaster address, or the double-bounce address. With
the default "<a href="postconf.5.html#owner_request_special">owner_request_special</a> = yes" setting, the <a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a>
is also not applied to addresses with the special "owner-" prefix
or the special "-request" suffix. </p>
<p>
Examples:
</p>
<pre>
# Handle Postfix-style extensions.
<a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a> = +
</pre>
<pre>
# Handle both Postfix and qmail extensions (Postfix 2.11 and later).
<a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a> = +-
</pre>
<pre>
# Use .forward for mail without address extension, and for mail with
# an unrecognized address extension.
<a href="postconf.5.html#forward_path">forward_path</a> = $home/.forward${<a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a>}${extension},
$home/.forward
</pre>
</DD>
<DT><b><a name="reject_code">reject_code</a>
(default: 554)</b></DT><DD>
<p>
The numerical Postfix SMTP server response code when a remote SMTP
client request is rejected by the "reject" restriction.
</p>
<p>
Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc5321">RFC 5321</a>.
</p>
</DD>
<DT><b><a name="reject_tempfail_action">reject_tempfail_action</a>
(default: <a href="postconf.5.html#defer_if_permit">defer_if_permit</a>)</b></DT><DD>
<p> The Postfix SMTP server's action when a reject-type restriction
fails due to a temporary error condition. Specify "defer" to defer
the remote SMTP client request immediately. With the default
"<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>" action, the Postfix SMTP server continues to look
for opportunities to reject mail, and defers the client request
only if it would otherwise be accepted. </p>
<p> For finer control, see: <a href="postconf.5.html#unverified_recipient_tempfail_action">unverified_recipient_tempfail_action</a>,
<a href="postconf.5.html#unverified_sender_tempfail_action">unverified_sender_tempfail_action</a>, <a href="postconf.5.html#unknown_address_tempfail_action">unknown_address_tempfail_action</a>,
and <a href="postconf.5.html#unknown_helo_hostname_tempfail_action">unknown_helo_hostname_tempfail_action</a>. </p>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="relay_clientcerts">relay_clientcerts</a>
(default: empty)</b></DT><DD>
<p> List of tables with remote SMTP client-certificate fingerprints or
public key fingerprints (Postfix 2.9 and later) for which the Postfix
SMTP server will allow access with the <a href="postconf.5.html#permit_tls_clientcerts">permit_tls_clientcerts</a>
feature. The fingerprint digest algorithm is configurable via the
<a href="postconf.5.html#smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a> parameter (hard-coded as md5 prior to
Postfix version 2.5). </p>
<p> Postfix lookup tables are in the form of (key, value) pairs.
Since we only need the key, the value can be chosen freely, e.g.
the name of the user or host:
D7:04:2F:A7:0B:8C:A5:21:FA:31:77:E1:41:8A:EE:80 lutzpc.at.home </p>
<p> Example: </p>
<pre>
<a href="postconf.5.html#relay_clientcerts">relay_clientcerts</a> = <a href="DATABASE_README.html#types">hash</a>:/etc/postfix/relay_clientcerts
</pre>
<p>For more fine-grained control, use <a href="postconf.5.html#check_ccert_access">check_ccert_access</a> to select
an appropriate <a href="access.5.html">access(5)</a> policy for each client.
See <a href="RESTRICTION_CLASS_README.html">RESTRICTION_CLASS_README</a>.</p>
<p> <b>Note:</b> Postfix 2.9.0–2.9.5 computed the public key
fingerprint incorrectly. To use public-key fingerprints, upgrade
to Postfix 2.9.6 or later. </p>
<p>This feature is available with Postfix version 2.2.</p>
</DD>
<DT><b><a name="relay_destination_concurrency_limit">relay_destination_concurrency_limit</a>
(default: $<a href="postconf.5.html#default_destination_concurrency_limit">default_destination_concurrency_limit</a>)</b></DT><DD>
<p> The maximal number of parallel deliveries to the same destination
via the relay message delivery transport. This limit is enforced
by the queue manager. The message delivery transport name is the
first field in the entry in the <a href="master.5.html">master.cf</a> file. </p>
<p> This feature is available in Postfix 2.0 and later. </p>
</DD>
<DT><b><a name="relay_destination_recipient_limit">relay_destination_recipient_limit</a>
(default: $<a href="postconf.5.html#default_destination_recipient_limit">default_destination_recipient_limit</a>)</b></DT><DD>
<p> The maximal number of recipients per message for the relay
message delivery transport. This limit is enforced by the queue
manager. The message delivery transport name is the first field in
the entry in the <a href="master.5.html">master.cf</a> file. </p>
<p> Setting this parameter to a value of 1 changes the meaning of
<a href="postconf.5.html#relay_destination_concurrency_limit">relay_destination_concurrency_limit</a> from concurrency per domain
into concurrency per recipient. </p>
<p> This feature is available in Postfix 2.0 and later. </p>
</DD>
<DT><b><a name="relay_domains">relay_domains</a>
(default: Postfix ≥ 3.0: empty, Postfix < 3.0: $<a href="postconf.5.html#mydestination">mydestination</a>)</b></DT><DD>
<p> What destination domains (and subdomains thereof) this system
will relay mail to. For details about how
the <a href="postconf.5.html#relay_domains">relay_domains</a> value is used, see the description of the
<a href="postconf.5.html#permit_auth_destination">permit_auth_destination</a> and <a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a> SMTP recipient
restrictions. </p>
<p> Domains that match $<a href="postconf.5.html#relay_domains">relay_domains</a> are delivered with the
$<a href="postconf.5.html#relay_transport">relay_transport</a> mail delivery transport. The SMTP server validates
recipient addresses with $<a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a> and rejects non-existent
recipients. See also the <a href="ADDRESS_CLASS_README.html#relay_domain_class">relay domains</a> address class in the
<a href="ADDRESS_CLASS_README.html">ADDRESS_CLASS_README</a> file. </p>
<p> Note: Postfix will not automatically forward mail for domains
that list this system as their primary or backup MX host. See the
<a href="postconf.5.html#permit_mx_backup">permit_mx_backup</a> restriction in the <a href="postconf.5.html">postconf(5)</a> manual page. </p>
<p> Specify a list of host or domain names, "/file/name" patterns
or "<a href="DATABASE_README.html">type:table</a>" lookup tables, separated by commas and/or whitespace.
Continue long lines by starting the next line with whitespace. A
"/file/name" pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>"
lookup table is matched when a (parent) domain appears as lookup
key. Specify "!pattern" to exclude a domain from the list. The form
"!/file/name" is supported only in Postfix version 2.4 and later.
</p>
<p> Pattern matching of domain names is controlled by the presence
or absence of "<a href="postconf.5.html#relay_domains">relay_domains</a>" in the <a href="postconf.5.html#parent_domain_matches_subdomains">parent_domain_matches_subdomains</a>
parameter value. </p>
</DD>
<DT><b><a name="relay_domains_reject_code">relay_domains_reject_code</a>
(default: 554)</b></DT><DD>
<p>
The numerical Postfix SMTP server response code when a client
request is rejected by the <a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a> recipient
restriction.
</p>
<p>
Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc5321">RFC 5321</a>.
</p>
</DD>
<DT><b><a name="relay_recipient_maps">relay_recipient_maps</a>
(default: empty)</b></DT><DD>
<p> Optional lookup tables with all valid addresses in the domains
that match $<a href="postconf.5.html#relay_domains">relay_domains</a>. Specify @domain as a wild-card for
domains that have no valid recipient list, and become a source of
backscatter mail: Postfix accepts spam for non-existent recipients
and then floods innocent people with undeliverable mail. Technically,
tables
listed with $<a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a> are used as lists: Postfix needs
to know only if a lookup string is found or not, but it does not
use the result from table lookup. </p>
<p>
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found.
</p>
<p>
If this parameter is non-empty, then the Postfix SMTP server will reject
mail to unknown relay users. This feature is off by default.
</p>
<p>
See also the <a href="ADDRESS_CLASS_README.html#relay_domain_class">relay domains</a> address class in the <a href="ADDRESS_CLASS_README.html">ADDRESS_CLASS_README</a>
file.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a> = <a href="DATABASE_README.html#types">hash</a>:/etc/postfix/relay_recipients
</pre>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="relay_transport">relay_transport</a>
(default: relay)</b></DT><DD>
<p>
The default mail delivery transport and next-hop destination for
remote delivery to domains listed with $<a href="postconf.5.html#relay_domains">relay_domains</a>. In order of
decreasing precedence, the nexthop destination is taken from
$<a href="postconf.5.html#relay_transport">relay_transport</a>, $<a href="postconf.5.html#sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a>, $<a href="postconf.5.html#relayhost">relayhost</a>, or
from the recipient domain. This information can be overruled with
the <a href="transport.5.html">transport(5)</a> table.
</p>
<p>
Specify a string of the form <i>transport:nexthop</i>, where <i>transport</i>
is the name of a mail delivery transport defined in <a href="master.5.html">master.cf</a>.
The <i>:nexthop</i> destination is optional; its syntax is documented
in the manual page of the corresponding delivery agent.
</p>
<p>
See also the <a href="ADDRESS_CLASS_README.html#relay_domain_class">relay domains</a> address class in the <a href="ADDRESS_CLASS_README.html">ADDRESS_CLASS_README</a>
file.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="relayhost">relayhost</a>
(default: empty)</b></DT><DD>
<p>
The next-hop destination of non-local mail; overrides non-local
domains in recipient addresses. This information is overruled with
<a href="postconf.5.html#relay_transport">relay_transport</a>, <a href="postconf.5.html#sender_dependent_default_transport_maps">sender_dependent_default_transport_maps</a>,
<a href="postconf.5.html#default_transport">default_transport</a>, <a href="postconf.5.html#sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a>
and with the <a href="transport.5.html">transport(5)</a> table.
</p>
<p>
On an intranet, specify the organizational domain name. If your
internal DNS uses no MX records, specify the name of the intranet
gateway host instead.
</p>
<p>
In the case of SMTP, specify a domain name, hostname, hostname:port,
[hostname]:port, [hostaddress] or [hostaddress]:port. The form
[hostname] turns off MX lookups.
</p>
<p>
If you're connected via UUCP, see the <a href="UUCP_README.html">UUCP_README</a> file for useful
information.
</p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#relayhost">relayhost</a> = $<a href="postconf.5.html#mydomain">mydomain</a>
<a href="postconf.5.html#relayhost">relayhost</a> = [gateway.example.com]
<a href="postconf.5.html#relayhost">relayhost</a> = uucphost
<a href="postconf.5.html#relayhost">relayhost</a> = [an.ip.add.ress]
</pre>
</DD>
<DT><b><a name="relocated_maps">relocated_maps</a>
(default: empty)</b></DT><DD>
<p>
Optional lookup tables with new contact information for users or
domains that no longer exist. The table format and lookups are
documented in <a href="relocated.5.html">relocated(5)</a>.
</p>
<p>
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found.
</p>
<p>
If you use this feature, run "<b>postmap /etc/postfix/relocated</b>" to
build the necessary DBM or DB file after change, then "<b>postfix
reload</b>" to make the changes visible.
</p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#relocated_maps">relocated_maps</a> = <a href="DATABASE_README.html#types">dbm</a>:/etc/postfix/relocated
<a href="postconf.5.html#relocated_maps">relocated_maps</a> = <a href="DATABASE_README.html#types">hash</a>:/etc/postfix/relocated
</pre>
</DD>
<DT><b><a name="remote_header_rewrite_domain">remote_header_rewrite_domain</a>
(default: empty)</b></DT><DD>
<p> Don't rewrite message headers from remote clients at all when
this parameter is empty; otherwise, rewrite message headers and
append the specified domain name to incomplete addresses. The
<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> parameter controls what clients Postfix
considers local. </p>
<p> Examples: </p>
<p> The safe setting: append "domain.invalid" to incomplete header
addresses from remote SMTP clients, so that those addresses cannot
be confused with local addresses. </p>
<blockquote>
<pre>
<a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> = domain.invalid
</pre>
</blockquote>
<p> The default, purist, setting: don't rewrite headers from remote
clients at all. </p>
<blockquote>
<pre>
<a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> =
</pre>
</blockquote>
</DD>
<DT><b><a name="require_home_directory">require_home_directory</a>
(default: no)</b></DT><DD>
<p>
Require that a <a href="local.8.html">local(8)</a> recipient's home directory exists
before mail delivery is attempted. By default this test is disabled.
It can be useful for environments that import home directories to
the mail server (IMPORTING HOME DIRECTORIES IS NOT RECOMMENDED).
</p>
</DD>
<DT><b><a name="reset_owner_alias">reset_owner_alias</a>
(default: no)</b></DT><DD>
<p> Reset the <a href="local.8.html">local(8)</a> delivery agent's idea of the owner-alias
attribute, when delivering mail to a child alias that does not have
its own owner alias. </p>
<p> This feature is available in Postfix 2.8 and later. With older
Postfix releases, the behavior is as if this parameter is set to
"yes". </p>
<p> As documented in <a href="aliases.5.html">aliases(5)</a>, when an alias <i>name</i> has a
companion alias named owner-<i>name</i>, this will replace the
envelope sender address, so that delivery errors will be
reported to the owner alias instead of the sender. This configuration
is recommended for mailing lists. <p>
<p> A less known property of the owner alias is that it also forces
the <a href="local.8.html">local(8)</a> delivery agent to write local and remote addresses
from alias expansion to a new queue file, instead of attempting to
deliver mail to local addresses as soon as they come out of alias
expansion. </p>
<p> Writing local addresses from alias expansion to a new queue
file allows for robust handling of temporary delivery errors: errors
with one local member have no effect on deliveries to other members
of the list. On the other hand, delivery to local addresses as
soon as they come out of alias expansion is fragile: a temporary
error with one local address from alias expansion will cause the
entire alias to be expanded repeatedly until the error goes away,
or until the message expires in the queue. In that case, a problem
with one list member results in multiple message deliveries to other
list members. </p>
<p> The default behavior of Postfix 2.8 and later is to keep the
owner-alias attribute of the parent alias, when delivering mail to
a child alias that does not have its own owner alias. Then, local
addresses from that child alias will be written to a new queue file,
and a temporary error with one local address will not affect delivery
to other mailing list members. </p>
<p> Unfortunately, older Postfix releases reset the owner-alias
attribute when delivering mail to a child alias that does not have
its own owner alias. To be precise, this resets only the decision
to create a new queue file, not the decision to override the envelope
sender address. The <a href="local.8.html">local(8)</a> delivery agent then attempts to
deliver local addresses as soon as they come out of child alias
expansion. If delivery to any address from child alias expansion
fails with a temporary error condition, the entire mailing list may
be expanded repeatedly until the mail expires in the queue, resulting
in multiple deliveries of the same message to mailing list members.
</p>
</DD>
<DT><b><a name="resolve_dequoted_address">resolve_dequoted_address</a>
(default: yes)</b></DT><DD>
<p> Resolve a recipient address safely instead of correctly, by
looking inside quotes. </p>
<p> By default, the Postfix address resolver does not quote the
address localpart as per <a href="http://tools.ietf.org/html/rfc822">RFC 822</a>, so that additional @ or % or !
operators remain visible. This behavior is safe but it is also
technically incorrect. </p>
<p> If you specify "<a href="postconf.5.html#resolve_dequoted_address">resolve_dequoted_address</a> = no", then
the Postfix
resolver will not know about additional @ etc. operators in the
address localpart. This opens opportunities for obscure mail relay
attacks with user@domain@domain addresses when Postfix provides
backup MX service for Sendmail systems. </p>
</DD>
<DT><b><a name="resolve_null_domain">resolve_null_domain</a>
(default: no)</b></DT><DD>
<p> Resolve an address that ends in the "@" null domain as if the
local hostname were specified, instead of rejecting the address as
invalid. </p>
<p> This feature is available in Postfix 2.1 and later.
Earlier versions always resolve the null domain as the local
hostname. </p>
<p> The Postfix SMTP server uses this feature to reject mail from
or to addresses that end in the "@" null domain, and from addresses
that rewrite into a form that ends in the "@" null domain. </p>
</DD>
<DT><b><a name="resolve_numeric_domain">resolve_numeric_domain</a>
(default: no)</b></DT><DD>
<p> Resolve "user@ipaddress" as "user@[ipaddress]", instead of
rejecting the address as invalid. </p>
<p> This feature is available in Postfix 2.3 and later.
</DD>
<DT><b><a name="rewrite_service_name">rewrite_service_name</a>
(default: rewrite)</b></DT><DD>
<p>
The name of the address rewriting service. This service rewrites
addresses to standard form and resolves them to a (delivery method,
next-hop host, recipient) triple.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="sample_directory">sample_directory</a>
(default: /etc/postfix)</b></DT><DD>
<p>
The name of the directory with example Postfix configuration files.
Starting with Postfix 2.1, these files have been replaced with the
<a href="postconf.5.html">postconf(5)</a> manual page.
</p>
</DD>
<DT><b><a name="send_cyrus_sasl_authzid">send_cyrus_sasl_authzid</a>
(default: no)</b></DT><DD>
<p> When authenticating to a remote SMTP or LMTP server with the
default setting "no", send no SASL authoriZation ID (authzid); send
only the SASL authentiCation ID (authcid) plus the authcid's password.
</p>
<p> The non-default setting "yes" enables the behavior of older
Postfix versions. These always send a SASL authzid that is equal
to the SASL authcid, but this causes interoperability problems
with some SMTP servers. </p>
<p> This feature is available in Postfix 2.4.4 and later. </p>
</DD>
<DT><b><a name="sender_based_routing">sender_based_routing</a>
(default: no)</b></DT><DD>
<p>
This parameter should not be used. It was replaced by <a href="postconf.5.html#sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a>
in Postfix version 2.3.
</p>
</DD>
<DT><b><a name="sender_bcc_maps">sender_bcc_maps</a>
(default: empty)</b></DT><DD>
<p> Optional BCC (blind carbon-copy) address lookup tables, indexed
by sender address. The BCC address (multiple results are not
supported) is added when mail enters from outside of Postfix. </p>
<p>
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found.
</p>
<p>
The table search order is as follows:
</p>
<ul>
<li> Look up the "user+extension@domain.tld" address including the
optional address extension.
<li> Look up the "user@domain.tld" address without the optional
address extension.
<li> Look up the "user+extension" address local part when the
sender domain equals $<a href="postconf.5.html#myorigin">myorigin</a>, $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>
or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>.
<li> Look up the "user" address local part when the sender domain
equals $<a href="postconf.5.html#myorigin">myorigin</a>, $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>.
<li> Look up the "@domain.tld" part.
</ul>
<p>
Note: with Postfix 2.3 and later the BCC address is added as if it
was specified with NOTIFY=NONE. The sender will not be notified
when the BCC address is undeliverable, as long as all down-stream
software implements <a href="http://tools.ietf.org/html/rfc3461">RFC 3461</a>.
</p>
<p>
Note: with Postfix 2.2 and earlier the sender will be notified
when the BCC address is undeliverable.
</p>
<p> Note: automatic BCC recipients are produced only for new mail.
To avoid mailer loops, automatic BCC recipients are not generated
after Postfix forwards mail internally, or after Postfix generates
mail itself. </p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#sender_bcc_maps">sender_bcc_maps</a> = <a href="DATABASE_README.html#types">hash</a>:/etc/postfix/sender_bcc
</pre>
<p>
After a change, run "<b>postmap /etc/postfix/sender_bcc</b>".
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="sender_canonical_classes">sender_canonical_classes</a>
(default: envelope_sender, header_sender)</b></DT><DD>
<p> What addresses are subject to <a href="postconf.5.html#sender_canonical_maps">sender_canonical_maps</a> address
mapping. By default, <a href="postconf.5.html#sender_canonical_maps">sender_canonical_maps</a> address mapping is
applied to envelope sender addresses, and to header sender addresses.
</p>
<p> Specify one or more of: envelope_sender, header_sender </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="sender_canonical_maps">sender_canonical_maps</a>
(default: empty)</b></DT><DD>
<p>
Optional address mapping lookup tables for envelope and header
sender addresses.
The table format and lookups are documented in <a href="canonical.5.html">canonical(5)</a>.
</p>
<p>
Example: you want to rewrite the SENDER address "user@ugly.domain"
to "user@pretty.domain", while still being able to send mail to
the RECIPIENT address "user@ugly.domain".
</p>
<p>
Note: $<a href="postconf.5.html#sender_canonical_maps">sender_canonical_maps</a> is processed before $<a href="postconf.5.html#canonical_maps">canonical_maps</a>.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#sender_canonical_maps">sender_canonical_maps</a> = <a href="DATABASE_README.html#types">hash</a>:/etc/postfix/sender_canonical
</pre>
</DD>
<DT><b><a name="sender_dependent_default_transport_maps">sender_dependent_default_transport_maps</a>
(default: empty)</b></DT><DD>
<p> A sender-dependent override for the global <a href="postconf.5.html#default_transport">default_transport</a>
parameter setting. The tables are searched by the envelope sender
address and @domain. A lookup result of DUNNO terminates the search
without overriding the global <a href="postconf.5.html#default_transport">default_transport</a> parameter setting.
This information is overruled with the <a href="transport.5.html">transport(5)</a> table. </p>
<p>
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found.
</p>
<p> Note: this overrides <a href="postconf.5.html#default_transport">default_transport</a>, not <a href="postconf.5.html#transport_maps">transport_maps</a>, and
therefore the expected syntax is that of <a href="postconf.5.html#default_transport">default_transport</a>, not the
syntax of <a href="postconf.5.html#transport_maps">transport_maps</a>. Specifically, this does not support the
<a href="postconf.5.html#transport_maps">transport_maps</a> syntax for null transport, null nexthop, or null
email addresses. </p>
<p> For safety reasons, this feature does not allow $number
substitutions in regular expression maps. </p>
<p> This feature is available in Postfix 2.7 and later. </p>
</DD>
<DT><b><a name="sender_dependent_relayhost_maps">sender_dependent_relayhost_maps</a>
(default: empty)</b></DT><DD>
<p> A sender-dependent override for the global <a href="postconf.5.html#relayhost">relayhost</a> parameter
setting. The tables are searched by the envelope sender address and
@domain. A lookup result of DUNNO terminates the search without
overriding the global <a href="postconf.5.html#relayhost">relayhost</a> parameter setting (Postfix 2.6 and
later). This information is overruled with <a href="postconf.5.html#relay_transport">relay_transport</a>,
<a href="postconf.5.html#sender_dependent_default_transport_maps">sender_dependent_default_transport_maps</a>, <a href="postconf.5.html#default_transport">default_transport</a> and with
the <a href="transport.5.html">transport(5)</a> table. </p>
<p>
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found.
</p>
<p> For safety reasons, this feature does not allow $number
substitutions in regular expression maps. </p>
<p>
This feature is available in Postfix 2.3 and later.
</p>
</DD>
<DT><b><a name="sendmail_fix_line_endings">sendmail_fix_line_endings</a>
(default: always)</b></DT><DD>
<p> Controls how the Postfix sendmail command converts email message
line endings from <CR><LF> into UNIX format (<LF>).
</p>
<dl>
<dt> <b>always</b> </dt> <dd> Always convert message lines ending
in <CR><LF>. This setting is the default with Postfix
2.9 and later. </dd>
<dt> <b>strict</b> </dt> <dd> Convert message lines ending in
<CR><LF> only if the first input line ends in
<CR><LF>. This setting is backwards-compatible with
Postfix 2.8 and earlier. </dd>
<dt> <b>never</b> </dt> <dd> Never convert message lines ending in
<CR><LF>. This setting exists for completeness only.
</dd>
</dl>
<p> This feature is available in Postfix 2.9 and later. </p>
</DD>
<DT><b><a name="sendmail_path">sendmail_path</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
A Sendmail compatibility feature that specifies the location of
the Postfix <a href="sendmail.1.html">sendmail(1)</a> command. This command can be used to
submit mail into the Postfix queue.
</p>
</DD>
<DT><b><a name="service_name">service_name</a>
(read-only)</b></DT><DD>
<p> The <a href="master.5.html">master.cf</a> service name of a Postfix daemon process. This
can be used to distinguish the logging from different services that
use the same program name. </p>
<p> Example <a href="master.5.html">master.cf</a> entries: </p>
<pre>
# Distinguish inbound MTA logging from submission and smtps logging.
smtp inet n - n - - smtpd
submission inet n - n - - smtpd
-o <a href="postconf.5.html#syslog_name">syslog_name</a>=postfix/$<a href="postconf.5.html#service_name">service_name</a>
smtps inet n - n - - smtpd
-o <a href="postconf.5.html#syslog_name">syslog_name</a>=postfix/$<a href="postconf.5.html#service_name">service_name</a>
</pre>
<pre>
# Distinguish outbound MTA logging from inbound relay logging.
smtp unix - - n - - smtp
relay unix - - n - - smtp
-o <a href="postconf.5.html#syslog_name">syslog_name</a>=postfix/$<a href="postconf.5.html#service_name">service_name</a>
</pre>
</DD>
<DT><b><a name="service_throttle_time">service_throttle_time</a>
(default: 60s)</b></DT><DD>
<p>
How long the Postfix <a href="master.8.html">master(8)</a> waits before forking a server that
appears to be malfunctioning.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="setgid_group">setgid_group</a>
(default: postdrop)</b></DT><DD>
<p>
The group ownership of set-gid Postfix commands and of group-writable
Postfix directories. When this parameter value is changed you need
to re-run "<b>postfix set-permissions</b>" (with Postfix version 2.0 and
earlier: "<b>/etc/postfix/post-install set-permissions</b>".
</p>
</DD>
<DT><b><a name="shlib_directory">shlib_directory</a>
(default: see 'postconf -d' output)</b></DT><DD>
<p> The location of Postfix dynamically-linked libraries
(libpostfix-*.so), and the default location of Postfix database
plugins (postfix-*.so) that have a relative pathname in the
dynamicmaps.cf file. The <a href="postconf.5.html#shlib_directory">shlib_directory</a> parameter defaults to
"no" when Postfix dynamically-linked libraries and database plugins
are disabled at compile time, otherwise it typically defaults to
/usr/lib/postfix or /usr/local/lib/postfix. </p>
<p> Notes: </p>
<ul>
<li> <p> The directory specified with <a href="postconf.5.html#shlib_directory">shlib_directory</a> should contain
only Postfix-related files. Postfix dynamically-linked libraries
and database plugins should not be installed in a "public" system
directory such as /usr/lib or /usr/local/lib. Linking Postfix
dynamically-linked library files or database plugins into non-Postfix
programs is not supported. Postfix dynamically-linked libraries
and database plugins implement a Postfix-internal API that changes
without maintaining compatibility. </p>
<li> <p> You can change the <a href="postconf.5.html#shlib_directory">shlib_directory</a> value after Postfix is
built. However, you may have to run ldconfig or equivalent to prevent
Postfix programs from failing because the libpostfix-*.so files are
not found. No ldconfig command is needed if you keep the libpostfix-*.so
files in the compiled-in default $<a href="postconf.5.html#shlib_directory">shlib_directory</a> location. </p>
</ul>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="show_user_unknown_table_name">show_user_unknown_table_name</a>
(default: yes)</b></DT><DD>
<p>
Display the name of the recipient table in the "User unknown"
responses. The extra detail makes trouble shooting easier but also
reveals information that is nobody elses business.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="showq_service_name">showq_service_name</a>
(default: showq)</b></DT><DD>
<p>
The name of the <a href="showq.8.html">showq(8)</a> service. This service produces mail queue
status reports.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="smtp_address_preference">smtp_address_preference</a>
(default: any)</b></DT><DD>
<p> The address type ("ipv6", "ipv4" or "any") that the Postfix
SMTP client will try first, when a destination has IPv6 and IPv4
addresses with equal MX preference. This feature has no effect
unless the <a href="postconf.5.html#inet_protocols">inet_protocols</a> setting enables both IPv4 and IPv6. </p>
<p> Postfix SMTP client address preference has evolved. With Postfix
2.8 the default is "ipv6"; earlier implementations are hard-coded
to prefer IPv6 over IPv4. </p>
<p> Notes for mail delivery between sites that have both IPv4 and
IPv6 connectivity: </p>
<ul>
<li> <p> The setting "<a href="postconf.5.html#smtp_address_preference">smtp_address_preference</a> = ipv6" is unsafe.
It can fail to deliver mail when there is an outage that affects
IPv6, while the destination is still reachable over IPv4. </p>
<li> <p> The setting "<a href="postconf.5.html#smtp_address_preference">smtp_address_preference</a> = any" is safe. With
this, mail will eventually be delivered even if there is an outage
that affects IPv6 or IPv4, as long as it does not affect both. </p>
</ul>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="smtp_address_verify_target">smtp_address_verify_target</a>
(default: rcpt)</b></DT><DD>
<p> In the context of email address verification, the SMTP protocol
stage that determines whether an email address is deliverable.
Specify one of "rcpt" or "data". The latter is needed with remote
SMTP servers that reject recipients after the DATA command. Use
<a href="postconf.5.html#transport_maps">transport_maps</a> to apply this feature selectively: </p>
<blockquote>
<pre>
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
<a href="postconf.5.html#transport_maps">transport_maps</a> = <a href="DATABASE_README.html#types">hash</a>:/etc/postfix/transport
</pre>
</blockquote>
<blockquote>
<pre>
/etc/postfix/transport:
smtp-domain-that-verifies-after-data smtp-data-target:
lmtp-domain-that-verifies-after-data lmtp-data-target:
</pre>
</blockquote>
<blockquote>
<pre>
/etc/postfix/<a href="master.5.html">master.cf</a>:
smtp-data-target unix - - n - - smtp
-o <a href="postconf.5.html#smtp_address_verify_target">smtp_address_verify_target</a>=data
lmtp-data-target unix - - n - - lmtp
-o <a href="postconf.5.html#lmtp_address_verify_target">lmtp_address_verify_target</a>=data
</pre>
</blockquote>
<p> Unselective use of the "data" target does no harm, but will
result in unnecessary "lost connection after DATA" events at remote
SMTP/LMTP servers. </p>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="smtp_always_send_ehlo">smtp_always_send_ehlo</a>
(default: yes)</b></DT><DD>
<p>
Always send EHLO at the start of an SMTP session.
</p>
<p>
With "<a href="postconf.5.html#smtp_always_send_ehlo">smtp_always_send_ehlo</a> = no", the Postfix SMTP client sends
EHLO only when
the word "ESMTP" appears in the server greeting banner (example:
220 spike.porcupine.org ESMTP Postfix).
</p>
</DD>
<DT><b><a name="smtp_balance_inet_protocols">smtp_balance_inet_protocols</a>
(default: yes)</b></DT><DD>
<p> When a remote destination resolves to a combination of IPv4 and
IPv6 addresses, ensure that the Postfix SMTP client can try both
address types before it runs into the <a href="postconf.5.html#smtp_mx_address_limit">smtp_mx_address_limit</a>. </p>
<p> This avoids an interoperability problem when a destination resolves
to primarily IPv6 addresses, the smtp_address_limit feature eliminates
most or all IPv4 addresses, and the destination is not reachable over
IPv6. </p>
<p> This feature is available in Postfix 3.3 and later. </p>
</DD>
<DT><b><a name="smtp_bind_address">smtp_bind_address</a>
(default: empty)</b></DT><DD>
<p>
An optional numerical network address that the Postfix SMTP client
should bind to when making an IPv4 connection.
</p>
<p>
This can be specified in the <a href="postconf.5.html">main.cf</a> file for all SMTP clients, or
it can be specified in the <a href="master.5.html">master.cf</a> file for a specific client,
for example:
</p>
<blockquote>
<pre>
/etc/postfix/<a href="master.5.html">master.cf</a>:
smtp ... smtp -o <a href="postconf.5.html#smtp_bind_address">smtp_bind_address</a>=11.22.33.44
</pre>
</blockquote>
<p> Note 1: when <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> specifies no more than one IPv4
address, and that address is a non-loopback address, it is
automatically used as the <a href="postconf.5.html#smtp_bind_address">smtp_bind_address</a>. This supports virtual
IP hosting, but can be a problem on multi-homed firewalls. See the
<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> documentation for more detail. </p>
<p> Note 2: address information may be enclosed inside <tt>[]</tt>,
but this form is not required here. </p>
</DD>
<DT><b><a name="smtp_bind_address6">smtp_bind_address6</a>
(default: empty)</b></DT><DD>
<p>
An optional numerical network address that the Postfix SMTP client
should bind to when making an IPv6 connection.
</p>
<p> This feature is available in Postfix 2.2 and later. </p>
<p>
This can be specified in the <a href="postconf.5.html">main.cf</a> file for all SMTP clients, or
it can be specified in the <a href="master.5.html">master.cf</a> file for a specific client,
for example:
</p>
<blockquote>
<pre>
/etc/postfix/<a href="master.5.html">master.cf</a>:
smtp ... smtp -o <a href="postconf.5.html#smtp_bind_address6">smtp_bind_address6</a>=1:2:3:4:5:6:7:8
</pre>
</blockquote>
<p> Note 1: when <a href="postconf.5.html#inet_interfaces">inet_interfaces</a> specifies no more than one IPv6
address, and that address is a non-loopback address, it is
automatically used as the <a href="postconf.5.html#smtp_bind_address6">smtp_bind_address6</a>. This supports virtual
IP hosting, but can be a problem on multi-homed firewalls. See the
<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> documentation for more detail. </p>
<p> Note 2: address information may be enclosed inside <tt>[]</tt>,
but this form is not recommended here. </p>
</DD>
<DT><b><a name="smtp_body_checks">smtp_body_checks</a>
(default: empty)</b></DT><DD>
<p> Restricted <a href="header_checks.5.html">body_checks(5)</a> tables for the Postfix SMTP client.
These tables are searched while mail is being delivered. Actions
that change the delivery time or destination are not available.
</p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="smtp_cname_overrides_servername">smtp_cname_overrides_servername</a>
(default: version dependent)</b></DT><DD>
<p> When the remote SMTP servername is a DNS CNAME, replace the
servername with the result from CNAME expansion for the purpose of
logging, SASL password lookup, TLS
policy decisions, or TLS certificate verification. The value "no"
hardens Postfix <a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> hostname-based policies against
false hostname information in DNS CNAME records, and makes SASL
password file lookups more predictable. This is the default setting
as of Postfix 2.3. </p>
<p> When DNS CNAME records are validated with secure DNS lookups
(<a href="postconf.5.html#smtp_dns_support_level">smtp_dns_support_level</a> = dnssec), they are always allowed to
override the above servername (Postfix 2.11 and later). </p>
<p> This feature is available in Postfix 2.2.9 and later. </p>
</DD>
<DT><b><a name="smtp_connect_timeout">smtp_connect_timeout</a>
(default: 30s)</b></DT><DD>
<p>
The Postfix SMTP client time limit for completing a TCP connection, or
zero (use the operating system built-in time limit).
</p>
<p>
When no connection can be made within the deadline, the Postfix
SMTP client
tries the next address on the mail exchanger list. Specify 0 to
disable the time limit (i.e. use whatever timeout is implemented by
the operating system).
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="smtp_connection_cache_destinations">smtp_connection_cache_destinations</a>
(default: empty)</b></DT><DD>
<p> Permanently enable SMTP connection caching for the specified
destinations. With SMTP connection caching, a connection is not
closed immediately after completion of a mail transaction. Instead,
the connection is kept open for up to $<a href="postconf.5.html#smtp_connection_cache_time_limit">smtp_connection_cache_time_limit</a>
seconds. This allows connections to be reused for other deliveries,
and can improve mail delivery performance. </p>
<p> Specify a comma or white space separated list of destinations
or pseudo-destinations: </p>
<ul>
<li> if mail is sent without a <a href="postconf.5.html#relayhost">relay host</a>: a domain name (the
right-hand side of an email address, without the [] around a numeric
IP address),
<li> if mail is sent via a <a href="postconf.5.html#relayhost">relay host</a>: a <a href="postconf.5.html#relayhost">relay host</a> name (without
[] or non-default TCP port), as specified in <a href="postconf.5.html">main.cf</a> or in the
transport map,
<li> if mail is sent via a UNIX-domain socket: a pathname (without
the unix: prefix),
<li> a /file/name with domain names and/or <a href="postconf.5.html#relayhost">relay host</a> names as
defined above,
<li> a "<a href="DATABASE_README.html">type:table</a>" with domain names and/or <a href="postconf.5.html#relayhost">relay host</a> names on
the left-hand side. The right-hand side result from "<a href="DATABASE_README.html">type:table</a>"
lookups is ignored.
</ul>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtp_connection_cache_on_demand">smtp_connection_cache_on_demand</a>
(default: yes)</b></DT><DD>
<p> Temporarily enable SMTP connection caching while a destination
has a high volume of mail in the <a href="QSHAPE_README.html#active_queue">active queue</a>. With SMTP connection
caching, a connection is not closed immediately after completion
of a mail transaction. Instead, the connection is kept open for
up to $<a href="postconf.5.html#smtp_connection_cache_time_limit">smtp_connection_cache_time_limit</a> seconds. This allows
connections to be reused for other deliveries, and can improve mail
delivery performance. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtp_connection_cache_time_limit">smtp_connection_cache_time_limit</a>
(default: 2s)</b></DT><DD>
<p> When SMTP connection caching is enabled, the amount of time that
an unused SMTP client socket is kept open before it is closed. Do
not specify larger values without permission from the remote sites.
</p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtp_connection_reuse_count_limit">smtp_connection_reuse_count_limit</a>
(default: 0)</b></DT><DD>
<p> When SMTP connection caching is enabled, the number of times
that an SMTP session may be reused before it is closed, or zero (no
limit). With a reuse count limit of N, a connection is used up to
N+1 times. </p>
<p> NOTE: This feature is unsafe. When a high-volume destination
has multiple inbound MTAs, then the slowest inbound MTA will attract
the most connections to that destination. This limitation does not
exist with the <a href="postconf.5.html#smtp_connection_reuse_time_limit">smtp_connection_reuse_time_limit</a> feature. </p>
<p> This feature is available in Postfix 2.11. </p>
</DD>
<DT><b><a name="smtp_connection_reuse_time_limit">smtp_connection_reuse_time_limit</a>
(default: 300s)</b></DT><DD>
<p> The amount of time during which Postfix will use an SMTP
connection repeatedly. The timer starts when the connection is
initiated (i.e. it includes the connect, greeting and helo latency,
in addition to the latencies of subsequent mail delivery transactions).
</p>
<p> This feature addresses a performance stability problem with
remote SMTP servers. This problem is not specific to Postfix: it
can happen when any MTA sends large amounts of SMTP email to a site
that has multiple MX hosts. </p>
<p> The problem starts when one of a set of MX hosts becomes slower
than the rest. Even though SMTP clients connect to fast and slow
MX hosts with equal probability, the slow MX host ends up with more
simultaneous inbound connections than the faster MX hosts, because
the slow MX host needs more time to serve each client request. </p>
<p> The slow MX host becomes a connection attractor. If one MX
host becomes N times slower than the rest, it dominates mail delivery
latency unless there are more than N fast MX hosts to counter the
effect. And if the number of MX hosts is smaller than N, the mail
delivery latency becomes effectively that of the slowest MX host
divided by the total number of MX hosts. </p>
<p> The solution uses connection caching in a way that differs from
Postfix version 2.2. By limiting the amount of time during which a connection
can be used repeatedly (instead of limiting the number of deliveries
over that connection), Postfix not only restores fairness in the
distribution of simultaneous connections across a set of MX hosts,
it also favors deliveries over connections that perform well, which
is exactly what we want. </p>
<p> The default reuse time limit, 300s, is comparable to the various
smtp transaction timeouts which are fair estimates of maximum excess
latency for a slow delivery. Note that hosts may accept thousands
of messages over a single connection within the default connection
reuse time limit. This number is much larger than the default Postfix
version 2.2 limit of 10 messages per cached connection. It may prove necessary
to lower the limit to avoid interoperability issues with MTAs that
exhibit bugs when many messages are delivered via a single connection.
A lower reuse time limit risks losing the benefit of connection
reuse when the average connection and mail delivery latency exceeds
the reuse time limit. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="smtp_data_done_timeout">smtp_data_done_timeout</a>
(default: 600s)</b></DT><DD>
<p>
The Postfix SMTP client time limit for sending the SMTP ".", and
for receiving the remote SMTP server response.
</p>
<p>
When no response is received within the deadline, a warning is
logged that the mail may be delivered multiple times.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="smtp_data_init_timeout">smtp_data_init_timeout</a>
(default: 120s)</b></DT><DD>
<p>
The Postfix SMTP client time limit for sending the SMTP DATA command,
and for receiving the remote SMTP server response.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="smtp_data_xfer_timeout">smtp_data_xfer_timeout</a>
(default: 180s)</b></DT><DD>
<p>
The Postfix SMTP client time limit for sending the SMTP message content.
When the connection makes no progress for more than $<a href="postconf.5.html#smtp_data_xfer_timeout">smtp_data_xfer_timeout</a>
seconds the Postfix SMTP client terminates the transfer.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="smtp_defer_if_no_mx_address_found">smtp_defer_if_no_mx_address_found</a>
(default: no)</b></DT><DD>
<p>
Defer mail delivery when no MX record resolves to an IP address.
</p>
<p>
The default (no) is to return the mail as undeliverable. With older
Postfix versions the default was to keep trying to deliver the mail
until someone fixed the MX record or until the mail was too old.
</p>
<p>
Note: the Postfix SMTP client always ignores MX records with equal
or worse preference
than the local MTA itself.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="smtp_delivery_status_filter">smtp_delivery_status_filter</a>
(default: $<a href="postconf.5.html#default_delivery_status_filter">default_delivery_status_filter</a>)</b></DT><DD>
<p> Optional filter for the <a href="smtp.8.html">smtp(8)</a> delivery agent to change the
delivery status code or explanatory text of successful or unsuccessful
deliveries. See <a href="postconf.5.html#default_delivery_status_filter">default_delivery_status_filter</a> for details. </p>
<p> NOTE: This feature modifies Postfix SMTP client error or non-error
messages that may or may not be derived from remote SMTP server
responses. In contrast, the <a href="postconf.5.html#smtp_reply_filter">smtp_reply_filter</a> feature modifies
remote SMTP server responses only. </p>
</DD>
<DT><b><a name="smtp_destination_concurrency_limit">smtp_destination_concurrency_limit</a>
(default: $<a href="postconf.5.html#default_destination_concurrency_limit">default_destination_concurrency_limit</a>)</b></DT><DD>
<p> The maximal number of parallel deliveries to the same destination
via the smtp message delivery transport. This limit is enforced by
the queue manager. The message delivery transport name is the first
field in the entry in the <a href="master.5.html">master.cf</a> file. </p>
</DD>
<DT><b><a name="smtp_destination_recipient_limit">smtp_destination_recipient_limit</a>
(default: $<a href="postconf.5.html#default_destination_recipient_limit">default_destination_recipient_limit</a>)</b></DT><DD>
<p> The maximal number of recipients per message for the smtp
message delivery transport. This limit is enforced by the queue
manager. The message delivery transport name is the first field in
the entry in the <a href="master.5.html">master.cf</a> file. </p>
<p> Setting this parameter to a value of 1 changes the meaning of
<a href="postconf.5.html#smtp_destination_concurrency_limit">smtp_destination_concurrency_limit</a> from concurrency per domain
into concurrency per recipient. </p>
</DD>
<DT><b><a name="smtp_discard_ehlo_keyword_address_maps">smtp_discard_ehlo_keyword_address_maps</a>
(default: empty)</b></DT><DD>
<p> Lookup tables, indexed by the remote SMTP server address, with
case insensitive lists of EHLO keywords (pipelining, starttls, auth,
etc.) that the Postfix SMTP client will ignore in the EHLO response from a
remote SMTP server. See <a href="postconf.5.html#smtp_discard_ehlo_keywords">smtp_discard_ehlo_keywords</a> for details. The
table is not indexed by hostname for consistency with
<a href="postconf.5.html#smtpd_discard_ehlo_keyword_address_maps">smtpd_discard_ehlo_keyword_address_maps</a>. </p>
<p>
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found.
</p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtp_discard_ehlo_keywords">smtp_discard_ehlo_keywords</a>
(default: empty)</b></DT><DD>
<p> A case insensitive list of EHLO keywords (pipelining, starttls,
auth, etc.) that the Postfix SMTP client will ignore in the EHLO
response from a remote SMTP server. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
<p> Notes: </p>
<ul>
<li> <p> Specify the <b>silent-discard</b> pseudo keyword to prevent
this action from being logged. </p>
<li> <p> Use the <a href="postconf.5.html#smtp_discard_ehlo_keyword_address_maps">smtp_discard_ehlo_keyword_address_maps</a> feature to
discard EHLO keywords selectively. </p>
</ul>
</DD>
<DT><b><a name="smtp_dns_reply_filter">smtp_dns_reply_filter</a>
(default: empty)</b></DT><DD>
<p> Optional filter for Postfix SMTP client DNS lookup results.
Specify zero or more lookup tables. The lookup tables are searched
in the given order for a match with the DNS lookup result, converted
to the following form: </p>
<pre>
<i>name ttl class type preference value</i>
</pre>
<p> The <i>class</i> field is always "IN", the <i>preference</i>
field exists only for MX records, the names of hosts, domains, etc.
end in ".", and those names are in ASCII form (xn--mumble form in
the case of UTF8 names). </p>
<p> When a match is found, the table lookup result specifies an
action. By default, the table query and the action name are
case-insensitive. Currently, only the <b>IGNORE</b> action is
implemented. </p>
<p> Notes: </p>
<ul>
<li> <p> Postfix DNS reply filters have no effect on implicit DNS
lookups through nsswitch.conf or equivalent mechanisms. </p>
<li> <p> The Postfix SMTP/LMTP client uses <a href="postconf.5.html#smtp_dns_reply_filter">smtp_dns_reply_filter</a>
and <a href="postconf.5.html#lmtp_dns_reply_filter">lmtp_dns_reply_filter</a> only to discover a remote SMTP or LMTP
service (record types MX, A, AAAAA, and TLSA). These lookups are
also made to implement the features <a href="postconf.5.html#reject_unverified_sender">reject_unverified_sender</a> and
<a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipient</a>. </p>
<li> <p> The Postfix SMTP/LMTP client defers mail delivery when
a filter removes all lookup results from a successful query. </p>
<li> <p> Postfix SMTP server uses <a href="postconf.5.html#smtpd_dns_reply_filter">smtpd_dns_reply_filter</a> only to
look up MX, A, AAAAA, and TXT records to implement the features
<a href="postconf.5.html#reject_unknown_helo_hostname">reject_unknown_helo_hostname</a>, <a href="postconf.5.html#reject_unknown_sender_domain">reject_unknown_sender_domain</a>,
<a href="postconf.5.html#reject_unknown_recipient_domain">reject_unknown_recipient_domain</a>, reject_rbl_*, and reject_rhsbl_*.
</p>
<li> <p> The Postfix SMTP server logs a warning or defers mail
delivery when a filter removes all lookup results from a successful
query. </p>
</ul>
<p> Example: ignore Google AAAA records in Postfix SMTP client DNS
lookups, because Google sometimes hard-rejects mail from IPv6 clients
with valid PTR etc. records. </p>
<pre>
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
<a href="postconf.5.html#smtp_dns_reply_filter">smtp_dns_reply_filter</a> = <a href="pcre_table.5.html">pcre</a>:/etc/postfix/smtp_dns_reply_filter
</pre>
<pre>
/etc/postfix/smtp_dns_reply_filter:
# /domain ttl IN AAAA address/ action, all case-insensitive.
# Note: the domain name ends in ".".
/^\S+\.google\.com\.\s+\S+\s+\S+\s+AAAA\s+/ IGNORE
</pre>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="smtp_dns_resolver_options">smtp_dns_resolver_options</a>
(default: empty)</b></DT><DD>
<p> DNS Resolver options for the Postfix SMTP client. Specify zero
or more of the following options, separated by comma or whitespace.
Option names are case-sensitive. Some options refer to domain names
that are specified in the file /etc/resolv.conf or equivalent. </p>
<dl>
<dt><b>res_defnames</b></dt>
<dd> Append the current domain name to single-component names (those
that do not contain a "." character). This can produce incorrect
results, and is the hard-coded behavior prior to Postfix 2.8. </dd>
<dt><b>res_dnsrch</b></dt>
<dd> Search for host names in the current domain and in parent
domains. This can produce incorrect results and is therefore not
recommended. </dd>
</dl>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="smtp_dns_support_level">smtp_dns_support_level</a>
(default: empty)</b></DT><DD>
<p> Level of DNS support in the Postfix SMTP client. With
"<a href="postconf.5.html#smtp_dns_support_level">smtp_dns_support_level</a>" left at its empty default value, the legacy
"<a href="postconf.5.html#disable_dns_lookups">disable_dns_lookups</a>" parameter controls whether DNS is enabled in
the Postfix SMTP client, otherwise the legacy parameter is ignored.
</p>
<p> Specify one of the following: </p>
<dl>
<dt><b>disabled</b></dt>
<dd>Disable DNS lookups. No MX lookups are performed and hostname
to address lookups are unconditionally "native". This setting is
not appropriate for hosts that deliver mail to the public Internet.
Some obsolete how-to documents recommend disabling DNS lookups in
some configurations with content_filters. This is no longer required
and strongly discouraged. </dd>
<dt><b>enabled</b></dt>
<dd>Enable DNS lookups. Nexthop destination domains not enclosed
in "[]" will be subject to MX lookups. If "dns" and "native" are
included in the "<a href="postconf.5.html#smtp_host_lookup">smtp_host_lookup</a>" parameter value, DNS will be
queried first to resolve MX-host A records, followed by "native"
lookups if no answer is found in DNS. </dd>
<dt><b>dnssec</b></dt>
<dd>Enable <a href="https://tools.ietf.org/html/rfc4033">DNSSEC</a>
lookups. The "dnssec" setting differs from the "enabled" setting
above in the following ways: <ul> <li>Any MX lookups will set
RES_USE_DNSSEC and RES_USE_EDNS0 to request DNSSEC-validated
responses. If the MX response is DNSSEC-validated the corresponding
hostnames are considered validated. <li> The address lookups of
validated hostnames are also validated, (provided of course
"<a href="postconf.5.html#smtp_host_lookup">smtp_host_lookup</a>" includes "dns", see below). <li>Temporary
failures in DNSSEC-enabled hostname-to-address resolution block any
"native" lookups. Additional "native" lookups only happen when
DNSSEC lookups hard-fail (NODATA or NXDOMAIN). </ul> </dd>
</dl>
<p> The Postfix SMTP client considers non-MX "[nexthop]" and
"[nexthop]:port" destinations equivalent to statically-validated
MX records of the form "nexthop. IN MX 0 nexthop." Therefore,
with "dnssec" support turned on, validated hostname-to-address
lookups apply to the nexthop domain of any "[nexthop]" or
"[nexthop]:port" destination. This is also true for LMTP "inet:host"
and "inet:host:port" destinations, as LMTP hostnames are never
subject to MX lookups. </p>
<p>The "dnssec" setting is recommended only if you plan to use the
<a href="TLS_README.html#client_tls_dane">dane</a> or <a
href="TLS_README.html#client_tls_dane">dane-only</a> TLS security
level, otherwise enabling DNSSEC support in Postfix offers no
additional security. Postfix DNSSEC support relies on an upstream
recursive nameserver that validates DNSSEC signatures. Such a DNS
server will always filter out forged DNS responses, even when Postfix
itself is not configured to use DNSSEC. </p>
<p> When using Postfix DANE support the "<a href="postconf.5.html#smtp_host_lookup">smtp_host_lookup</a>" parameter
should include "dns", as <a
href="https://tools.ietf.org/html/rfc7672">DANE</a> is not applicable
to hosts resolved via "native" lookups. </p>
<p> As mentioned above, Postfix is not a validating <a
href="https://tools.ietf.org/html/rfc4035#section-4.9">stub
resolver</a>; it relies on the system's configured DNSSEC-validating
<a href="https://tools.ietf.org/html/rfc4035#section-3.2">recursive
nameserver</a> to perform all DNSSEC validation. Since this
nameserver's DNSSEC-validated responses will be fully trusted, it
is strongly recommended that the MTA host have a local DNSSEC-validating
recursive caching nameserver listening on a loopback address, and
be configured to use only this nameserver for all lookups. Otherwise,
Postfix may remain subject to man-in-the-middle attacks that forge
responses from the recursive nameserver</p>
<p>DNSSEC support requires a version of Postfix compiled against a
reasonably-modern DNS resolver(3) library that implements the
RES_USE_DNSSEC and RES_USE_EDNS0 resolver options. </p>
<p> This feature is available in Postfix 2.11 and later. </p>
</DD>
<DT><b><a name="smtp_enforce_tls">smtp_enforce_tls</a>
(default: no)</b></DT><DD>
<p> Enforcement mode: require that remote SMTP servers use TLS
encryption, and never send mail in the clear. This also requires
that the remote SMTP server hostname matches the information in
the remote server certificate, and that the remote SMTP server
certificate was issued by a CA that is trusted by the Postfix SMTP
client. If the certificate doesn't verify or the hostname doesn't
match, delivery is deferred and mail stays in the queue. </p>
<p> The server hostname is matched against all names provided as
dNSNames in the SubjectAlternativeName. If no dNSNames are specified,
the CommonName is checked. The behavior may be changed with the
<a href="postconf.5.html#smtp_tls_enforce_peername">smtp_tls_enforce_peername</a> option. </p>
<p> This option is useful only if you are definitely sure that you
will only connect to servers that support <a href="http://tools.ietf.org/html/rfc2487">RFC 2487</a> _and_ that
provide valid server certificates. Typical use is for clients that
send all their email to a dedicated mailhub. </p>
<p> This feature is available in Postfix 2.2 and later. With
Postfix 2.3 and later use <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> instead. </p>
</DD>
<DT><b><a name="smtp_fallback_relay">smtp_fallback_relay</a>
(default: $<a href="postconf.5.html#fallback_relay">fallback_relay</a>)</b></DT><DD>
<p>
Optional list of relay hosts for SMTP destinations that can't be
found or that are unreachable. With Postfix 2.2 and earlier this
parameter is called <a href="postconf.5.html#fallback_relay">fallback_relay</a>. </p>
<p>
By default, mail is returned to the sender when a destination is
not found, and delivery is deferred when a destination is unreachable.
</p>
<p> With bulk email deliveries, it can be beneficial to run the
fallback relay MTA on the same host, so that it can reuse the sender
IP address. This speeds up deliveries that are delayed by IP-based
reputation systems (greylist, etc.). </p>
<p> The fallback relays must be SMTP destinations. Specify a domain,
host, host:port, [host]:port, [address] or [address]:port; the form
[host] turns off MX lookups. If you specify multiple SMTP
destinations, Postfix will try them in the specified order. </p>
<p> To prevent mailer loops between MX hosts and fall-back hosts,
Postfix version 2.2 and later will not use the fallback relays for
destinations that it is MX host for (assuming DNS lookup is turned on).
</p>
</DD>
<DT><b><a name="smtp_generic_maps">smtp_generic_maps</a>
(default: empty)</b></DT><DD>
<p> Optional lookup tables that perform address rewriting in the
Postfix SMTP client, typically to transform a locally valid address into
a globally valid address when sending mail across the Internet.
This is needed when the local machine does not have its own Internet
domain name, but uses something like <i>localdomain.local</i>
instead. </p>
<p>
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found.
</p>
<p> The table format and lookups are documented in <a href="generic.5.html">generic(5)</a>;
examples are shown in the <a href="ADDRESS_REWRITING_README.html">ADDRESS_REWRITING_README</a> and
<a href="STANDARD_CONFIGURATION_README.html">STANDARD_CONFIGURATION_README</a> documents. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtp_header_checks">smtp_header_checks</a>
(default: empty)</b></DT><DD>
<p> Restricted <a href="header_checks.5.html">header_checks(5)</a> tables for the Postfix SMTP client.
These tables are searched while mail is being delivered. Actions
that change the delivery time or destination are not available.
</p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="smtp_helo_name">smtp_helo_name</a>
(default: $<a href="postconf.5.html#myhostname">myhostname</a>)</b></DT><DD>
<p>
The hostname to send in the SMTP HELO or EHLO command.
</p>
<p>
The default value is the machine hostname. Specify a hostname or
[ip.add.re.ss].
</p>
<p>
This information can be specified in the <a href="postconf.5.html">main.cf</a> file for all SMTP
clients, or it can be specified in the <a href="master.5.html">master.cf</a> file for a specific
client, for example:
</p>
<blockquote>
<pre>
/etc/postfix/<a href="master.5.html">master.cf</a>:
mysmtp ... smtp -o <a href="postconf.5.html#smtp_helo_name">smtp_helo_name</a>=foo.bar.com
</pre>
</blockquote>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="smtp_helo_timeout">smtp_helo_timeout</a>
(default: 300s)</b></DT><DD>
<p>
The Postfix SMTP client time limit for sending the HELO or EHLO command,
and for receiving the initial remote SMTP server response.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="smtp_host_lookup">smtp_host_lookup</a>
(default: dns)</b></DT><DD>
<p>
What mechanisms the Postfix SMTP client uses to look up a host's
IP address. This parameter is ignored when DNS lookups are disabled
(see: <a href="postconf.5.html#disable_dns_lookups">disable_dns_lookups</a> and <a href="postconf.5.html#smtp_dns_support_level">smtp_dns_support_level</a>). The "dns"
mechanism is always tried before "native" if both are listed.
</p>
<p>
Specify one of the following:
</p>
<dl>
<dt><b>dns</b></dt>
<dd>Hosts can be found in the DNS (preferred). </dd>
<dt><b>native</b></dt>
<dd>Use the native naming service only (nsswitch.conf, or equivalent
mechanism). </dd>
<dt><b>dns, native</b></dt>
<dd>Use the native service for hosts not found in the DNS. </dd>
</dl>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="smtp_line_length_limit">smtp_line_length_limit</a>
(default: 998)</b></DT><DD>
<p>
The maximal length of message header and body lines that Postfix
will send via SMTP. This limit does not include the <CR><LF>
at the end of each line. Longer lines are broken by inserting
"<CR><LF><SPACE>", to minimize the damage to MIME
formatted mail.
</p>
<p>
The Postfix limit of 998 characters not including <CR><LF>
is consistent with the SMTP limit of 1000 characters including
<CR><LF>. The Postfix limit was 990 with Postfix 2.8
and earlier.
</p>
</DD>
<DT><b><a name="smtp_mail_timeout">smtp_mail_timeout</a>
(default: 300s)</b></DT><DD>
<p>
The Postfix SMTP client time limit for sending the MAIL FROM command,
and for receiving the remote SMTP server response.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="smtp_mime_header_checks">smtp_mime_header_checks</a>
(default: empty)</b></DT><DD>
<p> Restricted mime_<a href="header_checks.5.html">header_checks(5)</a> tables for the Postfix SMTP
client. These tables are searched while mail is being delivered.
Actions that change the delivery time or destination are not
available. </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="smtp_mx_address_limit">smtp_mx_address_limit</a>
(default: 5)</b></DT><DD>
<p>
The maximal number of MX (mail exchanger) IP addresses that can
result from Postfix SMTP client mail exchanger lookups, or zero (no
limit). Prior to
Postfix version 2.3, this limit was disabled by default.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="smtp_mx_session_limit">smtp_mx_session_limit</a>
(default: 2)</b></DT><DD>
<p> The maximal number of SMTP sessions per delivery request before
the Postfix SMTP client
gives up or delivers to a fall-back <a href="postconf.5.html#relayhost">relay host</a>, or zero (no
limit). This restriction ignores sessions that fail to complete the
SMTP initial handshake (Postfix version 2.2 and earlier) or that fail to
complete the EHLO and TLS handshake (Postfix version 2.3 and later). </p>
<p> This feature is available in Postfix 2.1 and later. </p>
</DD>
<DT><b><a name="smtp_nested_header_checks">smtp_nested_header_checks</a>
(default: empty)</b></DT><DD>
<p> Restricted nested_<a href="header_checks.5.html">header_checks(5)</a> tables for the Postfix SMTP
client. These tables are searched while mail is being delivered.
Actions that change the delivery time or destination are not
available. </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="smtp_never_send_ehlo">smtp_never_send_ehlo</a>
(default: no)</b></DT><DD>
<p> Never send EHLO at the start of an SMTP session. See also the
<a href="postconf.5.html#smtp_always_send_ehlo">smtp_always_send_ehlo</a> parameter. </p>
</DD>
<DT><b><a name="smtp_per_record_deadline">smtp_per_record_deadline</a>
(default: no)</b></DT><DD>
<p> Change the behavior of the smtp_*_timeout time limits, from a
time limit per read or write system call, to a time limit to send
or receive a complete record (an SMTP command line, SMTP response
line, SMTP message content line, or TLS protocol message). This
limits the impact from hostile peers that trickle data one byte at
a time. </p>
<p> Note: when per-record deadlines are enabled, a short timeout
may cause problems with TLS over very slow network connections.
The reasons are that a TLS protocol message can be up to 16 kbytes
long (with TLSv1), and that an entire TLS protocol message must be
sent or received within the per-record deadline. </p>
<p> This feature is available in Postfix 2.9 and later. With older
Postfix releases, the behavior is as if this parameter is set to
"no". </p>
</DD>
<DT><b><a name="smtp_pix_workaround_delay_time">smtp_pix_workaround_delay_time</a>
(default: 10s)</b></DT><DD>
<p>
How long the Postfix SMTP client pauses before sending
".<CR><LF>" in order to work around the PIX firewall
"<CR><LF>.<CR><LF>" bug.
</p>
<p>
Choosing a too short time makes this workaround ineffective when
sending large messages over slow network connections.
</p>
</DD>
<DT><b><a name="smtp_pix_workaround_maps">smtp_pix_workaround_maps</a>
(default: empty)</b></DT><DD>
<p> Lookup tables, indexed by the remote SMTP server address, with
per-destination workarounds for CISCO PIX firewall bugs. The table
is not indexed by hostname for consistency with
<a href="postconf.5.html#smtp_discard_ehlo_keyword_address_maps">smtp_discard_ehlo_keyword_address_maps</a>. </p>
<p>
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found.
</p>
<p> This feature is available in Postfix 2.4 and later. </p>
</DD>
<DT><b><a name="smtp_pix_workaround_threshold_time">smtp_pix_workaround_threshold_time</a>
(default: 500s)</b></DT><DD>
<p> How long a message must be queued before the Postfix SMTP client
turns on the PIX firewall "<CR><LF>.<CR><LF>"
bug workaround for delivery through firewalls with "smtp fixup"
mode turned on. </p>
<p>
By default, the workaround is turned off for mail that is queued
for less than 500 seconds. In other words, the workaround is normally
turned off for the first delivery attempt.
</p>
<p>
Specify 0 to enable the PIX firewall
"<CR><LF>.<CR><LF>" bug workaround upon the
first delivery attempt.
</p>
</DD>
<DT><b><a name="smtp_pix_workarounds">smtp_pix_workarounds</a>
(default: disable_esmtp, delay_dotcrlf)</b></DT><DD>
<p> A list that specifies zero or more workarounds for CISCO PIX
firewall bugs. These workarounds are implemented by the Postfix
SMTP client. Workaround names are separated by comma or space, and
are case insensitive. This parameter setting can be overruled with
per-destination <a href="postconf.5.html#smtp_pix_workaround_maps">smtp_pix_workaround_maps</a> settings. </p>
<dl>
<dt><b>delay_dotcrlf</b><dd> Insert a delay before sending
".<CR><LF>" after the end of the message content. The
delay is subject to the <a href="postconf.5.html#smtp_pix_workaround_delay_time">smtp_pix_workaround_delay_time</a> and
<a href="postconf.5.html#smtp_pix_workaround_threshold_time">smtp_pix_workaround_threshold_time</a> parameter settings. </dd>
<dt><b>disable_esmtp</b><dd> Disable all extended SMTP commands:
send HELO instead of EHLO. </dd>
</dl>
<p> This feature is available in Postfix 2.4 and later. The default
settings are backwards compatible with earlier Postfix versions.
</p>
</DD>
<DT><b><a name="smtp_quit_timeout">smtp_quit_timeout</a>
(default: 300s)</b></DT><DD>
<p>
The Postfix SMTP client time limit for sending the QUIT command,
and for receiving the remote SMTP server response.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="smtp_quote_rfc821_envelope">smtp_quote_rfc821_envelope</a>
(default: yes)</b></DT><DD>
<p>
Quote addresses in Postfix SMTP client MAIL FROM and RCPT TO commands
as required
by <a href="http://tools.ietf.org/html/rfc5321">RFC 5321</a>. This includes putting quotes around an address localpart
that ends in ".".
</p>
<p>
The default is to comply with <a href="http://tools.ietf.org/html/rfc5321">RFC 5321</a>. If you have to send mail to
a broken SMTP server, configure a special SMTP client in <a href="master.5.html">master.cf</a>:
</p>
<blockquote>
<pre>
/etc/postfix/<a href="master.5.html">master.cf</a>:
broken-smtp . . . smtp -o <a href="postconf.5.html#smtp_quote_rfc821_envelope">smtp_quote_rfc821_envelope</a>=no
</pre>
</blockquote>
<p>
and route mail for the destination in question to the "broken-smtp"
message delivery with a <a href="transport.5.html">transport(5)</a> table.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="smtp_randomize_addresses">smtp_randomize_addresses</a>
(default: yes)</b></DT><DD>
<p>
Randomize the order of equal-preference MX host addresses. This
is a performance feature of the Postfix SMTP client.
</p>
</DD>
<DT><b><a name="smtp_rcpt_timeout">smtp_rcpt_timeout</a>
(default: 300s)</b></DT><DD>
<p>
The Postfix SMTP client time limit for sending the SMTP RCPT TO
command, and for receiving the remote SMTP server response.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="smtp_reply_filter">smtp_reply_filter</a>
(default: empty)</b></DT><DD>
<p> A mechanism to transform replies from remote SMTP servers one
line at a time. This is a last-resort tool to work around server
replies that break interoperability with the Postfix SMTP client.
Other uses involve fault injection to test Postfix's handling of
invalid responses. </p>
<p> Notes: </p>
<ul>
<li> <p> In the case of a multi-line reply, the Postfix SMTP client
uses the final reply line's numerical SMTP reply code and enhanced
status code. </p>
<li> <p> The numerical SMTP reply code (XYZ) takes precedence over
the enhanced status code (X.Y.Z). When the enhanced status code
initial digit differs from the SMTP reply code initial digit, or
when no enhanced status code is present, the Postfix SMTP client
uses a generic enhanced status code (X.0.0) instead. </p>
</ul>
<p> Specify the name of a "<a href="DATABASE_README.html">type:table</a>" lookup table. The search
string is a single SMTP reply line as received from the remote SMTP
server, except that the trailing <CR><LF> are removed.
When the lookup succeeds, the result replaces the single SMTP reply
line. </p>
<p> Examples: </p>
<pre>
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
<a href="postconf.5.html#smtp_reply_filter">smtp_reply_filter</a> = <a href="pcre_table.5.html">pcre</a>:/etc/postfix/reply_filter
</pre>
<pre>
/etc/postfix/reply_filter:
# Transform garbage into "250-filler..." so that it looks like
# one line from a multi-line reply. It does not matter what we
# substitute here as long it has the right syntax. The Postfix
# SMTP client will use the final line's numerical SMTP reply
# code and enhanced status code.
!/^([2-5][0-9][0-9]($|[- ]))/ 250-filler for garbage
</pre>
<p> This feature is available in Postfix 2.7. </p>
</DD>
<DT><b><a name="smtp_rset_timeout">smtp_rset_timeout</a>
(default: 20s)</b></DT><DD>
<p> The Postfix SMTP client time limit for sending the RSET command,
and for receiving the remote SMTP server response. The SMTP client
sends RSET in
order to finish a recipient address probe, or to verify that a
cached session is still usable. </p>
<p> This feature is available in Postfix 2.1 and later. </p>
</DD>
<DT><b><a name="smtp_sasl_auth_cache_name">smtp_sasl_auth_cache_name</a>
(default: empty)</b></DT><DD>
<p> An optional table to prevent repeated SASL authentication
failures with the same remote SMTP server hostname, username and
password. Each table (key, value) pair contains a server name, a
username and password, and the full server response. This information
is stored when a remote SMTP server rejects an authentication attempt
with a 535 reply code. As long as the <a href="postconf.5.html#smtp_sasl_password_maps">smtp_sasl_password_maps</a>
information does no change, and as long as the <a href="postconf.5.html#smtp_sasl_auth_cache_name">smtp_sasl_auth_cache_name</a>
information does not expire (see <a href="postconf.5.html#smtp_sasl_auth_cache_time">smtp_sasl_auth_cache_time</a>) the
Postfix SMTP client avoids SASL authentication attempts with the
same server, username and password, and instead bounces or defers
mail as controlled with the <a href="postconf.5.html#smtp_sasl_auth_soft_bounce">smtp_sasl_auth_soft_bounce</a> configuration
parameter. </p>
<p> Use a per-destination delivery concurrency of 1 (for example,
"<a href="postconf.5.html#smtp_destination_concurrency_limit">smtp_destination_concurrency_limit</a> = 1",
"<a href="postconf.5.html#relay_destination_concurrency_limit">relay_destination_concurrency_limit</a> = 1", etc.), otherwise multiple
delivery agents may experience a login failure at the same time.
</p>
<p> The table must be accessed via the proxywrite service, i.e. the
map name must start with "<a href="proxymap.8.html">proxy</a>:". The table should be stored under
the directory specified with the <a href="postconf.5.html#data_directory">data_directory</a> parameter. </p>
<p> This feature uses cryptographic hashing to protect plain-text
passwords, and requires that Postfix is compiled with TLS support.
</p>
<p> Example: </p>
<pre>
<a href="postconf.5.html#smtp_sasl_auth_cache_name">smtp_sasl_auth_cache_name</a> = <a href="proxymap.8.html">proxy</a>:<a href="DATABASE_README.html#types">btree</a>:/var/lib/postfix/sasl_auth_cache
</pre>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="smtp_sasl_auth_cache_time">smtp_sasl_auth_cache_time</a>
(default: 90d)</b></DT><DD>
<p> The maximal age of an <a href="postconf.5.html#smtp_sasl_auth_cache_name">smtp_sasl_auth_cache_name</a> entry before it
is removed. </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="smtp_sasl_auth_enable">smtp_sasl_auth_enable</a>
(default: no)</b></DT><DD>
<p>
Enable SASL authentication in the Postfix SMTP client. By default,
the Postfix SMTP client uses no authentication.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#smtp_sasl_auth_enable">smtp_sasl_auth_enable</a> = yes
</pre>
</DD>
<DT><b><a name="smtp_sasl_auth_soft_bounce">smtp_sasl_auth_soft_bounce</a>
(default: yes)</b></DT><DD>
<p> When a remote SMTP server rejects a SASL authentication request
with a 535 reply code, defer mail delivery instead of returning
mail as undeliverable. The latter behavior was hard-coded prior to
Postfix version 2.5. </p>
<p> Note: the setting "yes" overrides the global <a href="postconf.5.html#soft_bounce">soft_bounce</a>
parameter, but the setting "no" does not. </p>
<p> Example: </p>
<pre>
# Default as of Postfix 2.5
<a href="postconf.5.html#smtp_sasl_auth_soft_bounce">smtp_sasl_auth_soft_bounce</a> = yes
# The old hard-coded default
<a href="postconf.5.html#smtp_sasl_auth_soft_bounce">smtp_sasl_auth_soft_bounce</a> = no
</pre>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="smtp_sasl_mechanism_filter">smtp_sasl_mechanism_filter</a>
(default: empty)</b></DT><DD>
<p>
If non-empty, a Postfix SMTP client filter for the remote SMTP
server's list of offered SASL mechanisms. Different client and
server implementations may support different mechanism lists; by
default, the Postfix SMTP client will use the intersection of the
two. <a href="postconf.5.html#smtp_sasl_mechanism_filter">smtp_sasl_mechanism_filter</a> specifies an optional third mechanism
list to intersect with. </p>
<p> Specify mechanism names, "/file/name" patterns or "<a href="DATABASE_README.html">type:table</a>"
lookup tables. The right-hand side result from "<a href="DATABASE_README.html">type:table</a>" lookups
is ignored. Specify "!pattern" to exclude a mechanism name from the
list. The form "!/file/name" is supported only in Postfix version
2.4 and later. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#smtp_sasl_mechanism_filter">smtp_sasl_mechanism_filter</a> = plain, login
<a href="postconf.5.html#smtp_sasl_mechanism_filter">smtp_sasl_mechanism_filter</a> = /etc/postfix/smtp_mechs
<a href="postconf.5.html#smtp_sasl_mechanism_filter">smtp_sasl_mechanism_filter</a> = !gssapi, !login, <a href="DATABASE_README.html#types">static</a>:rest
</pre>
</DD>
<DT><b><a name="smtp_sasl_password_maps">smtp_sasl_password_maps</a>
(default: empty)</b></DT><DD>
<p>
Optional Postfix SMTP client lookup tables with one username:password
entry per sender, remote hostname or next-hop domain. Per-sender
lookup is done only when sender-dependent authentication is enabled.
If no username:password entry is found, then the Postfix SMTP client
will not attempt to authenticate to the remote host.
</p>
<p>
The Postfix SMTP client opens the lookup table before going to
chroot jail, so you can leave the password file in /etc/postfix.
</p>
<p>
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found.
</p>
</DD>
<DT><b><a name="smtp_sasl_path">smtp_sasl_path</a>
(default: empty)</b></DT><DD>
<p> Implementation-specific information that the Postfix SMTP client
passes through to
the SASL plug-in implementation that is selected with
<b><a href="postconf.5.html#smtp_sasl_type">smtp_sasl_type</a></b>. Typically this specifies the name of a
configuration file or rendezvous point. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="smtp_sasl_security_options">smtp_sasl_security_options</a>
(default: noplaintext, noanonymous)</b></DT><DD>
<p> Postfix SMTP client SASL security options; as of Postfix 2.3
the list of available
features depends on the SASL client implementation that is selected
with <b><a href="postconf.5.html#smtp_sasl_type">smtp_sasl_type</a></b>. </p>
<p> The following security features are defined for the <b>cyrus</b>
client SASL implementation: </p>
<p>
Specify zero or more of the following:
</p>
<dl>
<dt><b>noplaintext</b></dt>
<dd>Disallow methods that use plaintext passwords. </dd>
<dt><b>noactive</b></dt>
<dd>Disallow methods subject to active (non-dictionary) attack.
</dd>
<dt><b>nodictionary</b></dt>
<dd>Disallow methods subject to passive (dictionary) attack. </dd>
<dt><b>noanonymous</b></dt>
<dd>Disallow methods that allow anonymous authentication. </dd>
<dt><b>mutual_auth</b></dt>
<dd>Only allow methods that provide mutual authentication (not
available with SASL version 1). </dd>
</dl>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#smtp_sasl_security_options">smtp_sasl_security_options</a> = noplaintext
</pre>
</DD>
<DT><b><a name="smtp_sasl_tls_security_options">smtp_sasl_tls_security_options</a>
(default: $<a href="postconf.5.html#smtp_sasl_security_options">smtp_sasl_security_options</a>)</b></DT><DD>
<p> The SASL authentication security options that the Postfix SMTP
client uses for TLS encrypted SMTP sessions. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtp_sasl_tls_verified_security_options">smtp_sasl_tls_verified_security_options</a>
(default: $<a href="postconf.5.html#smtp_sasl_tls_security_options">smtp_sasl_tls_security_options</a>)</b></DT><DD>
<p> The SASL authentication security options that the Postfix SMTP
client uses for TLS encrypted SMTP sessions with a verified server
certificate. </p>
<p> When mail is sent to the public MX host for the recipient's
domain, server certificates are by default optional, and delivery
proceeds even if certificate verification fails. For delivery via
a submission service that requires SASL authentication, it may be
appropriate to send plaintext passwords only when the connection
to the server is strongly encrypted <b>and</b> the server identity
is verified. </p>
<p> The <a href="postconf.5.html#smtp_sasl_tls_verified_security_options">smtp_sasl_tls_verified_security_options</a> parameter makes it
possible to only enable plaintext mechanisms when a secure connection
to the server is available. Submission servers subject to this
policy must either have verifiable certificates or offer suitable
non-plaintext SASL mechanisms. </p>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="smtp_sasl_type">smtp_sasl_type</a>
(default: cyrus)</b></DT><DD>
<p> The SASL plug-in type that the Postfix SMTP client should use
for authentication. The available types are listed with the
"<b>postconf -A</b>" command. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="smtp_send_dummy_mail_auth">smtp_send_dummy_mail_auth</a>
(default: no)</b></DT><DD>
<p> Whether or not to append the "AUTH=<>" option to the MAIL
FROM command in SASL-authenticated SMTP sessions. The default is
not to send this, to avoid problems with broken remote SMTP servers.
Before Postfix 2.9 the behavior is as if "<a href="postconf.5.html#smtp_send_dummy_mail_auth">smtp_send_dummy_mail_auth</a>
= yes".
<p> This feature is available in Postfix 2.9 and later. </p>
</DD>
<DT><b><a name="smtp_send_xforward_command">smtp_send_xforward_command</a>
(default: no)</b></DT><DD>
<p>
Send the non-standard XFORWARD command when the Postfix SMTP server
EHLO response announces XFORWARD support.
</p>
<p>
This allows a Postfix SMTP delivery agent, used for injecting mail
into
a content filter, to forward the name, address, protocol and HELO
name of the original client to the content filter and downstream
queuing SMTP server. This can produce more useful logging than
localhost[127.0.0.1] etc.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="smtp_sender_dependent_authentication">smtp_sender_dependent_authentication</a>
(default: no)</b></DT><DD>
<p>
Enable sender-dependent authentication in the Postfix SMTP client; this is
available only with SASL authentication, and disables SMTP connection
caching to ensure that mail from different senders will use the
appropriate credentials. </p>
<p>
This feature is available in Postfix 2.3 and later.
</p>
</DD>
<DT><b><a name="smtp_skip_4xx_greeting">smtp_skip_4xx_greeting</a>
(default: yes)</b></DT><DD>
<p>
Skip SMTP servers that greet with a 4XX status code (go away, try
again later).
</p>
<p>
By default, the Postfix SMTP client moves on the next mail exchanger.
Specify
"<a href="postconf.5.html#smtp_skip_4xx_greeting">smtp_skip_4xx_greeting</a> = no" if Postfix should defer delivery
immediately.
</p>
<p> This feature is available in Postfix 2.0 and earlier.
Later Postfix versions always skip remote SMTP servers that greet
with a
4XX status code. </p>
</DD>
<DT><b><a name="smtp_skip_5xx_greeting">smtp_skip_5xx_greeting</a>
(default: yes)</b></DT><DD>
<p>
Skip remote SMTP servers that greet with a 5XX status code.
</p>
<p> By default, the Postfix SMTP client moves on the next mail
exchanger. Specify "<a href="postconf.5.html#smtp_skip_5xx_greeting">smtp_skip_5xx_greeting</a> = no" if Postfix should
bounce the mail immediately. Caution: the latter behavior appears
to contradict <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a>. </p>
</DD>
<DT><b><a name="smtp_skip_quit_response">smtp_skip_quit_response</a>
(default: yes)</b></DT><DD>
<p>
Do not wait for the response to the SMTP QUIT command.
</p>
</DD>
<DT><b><a name="smtp_starttls_timeout">smtp_starttls_timeout</a>
(default: 300s)</b></DT><DD>
<p> Time limit for Postfix SMTP client write and read operations
during TLS startup and shutdown handshake procedures. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtp_tcp_port">smtp_tcp_port</a>
(default: smtp)</b></DT><DD>
<p>
The default TCP port that the Postfix SMTP client connects to.
Specify a symbolic name (see services(5)) or a numeric port.
</p>
</DD>
<DT><b><a name="smtp_tls_CAfile">smtp_tls_CAfile</a>
(default: empty)</b></DT><DD>
<p> A file containing CA certificates of root CAs trusted to sign
either remote SMTP server certificates or intermediate CA certificates.
These are loaded into memory before the <a href="smtp.8.html">smtp(8)</a> client enters the
chroot jail. If the number of trusted roots is large, consider using
<a href="postconf.5.html#smtp_tls_CApath">smtp_tls_CApath</a> instead, but note that the latter directory must be
present in the chroot jail if the <a href="smtp.8.html">smtp(8)</a> client is chrooted. This
file may also be used to augment the client certificate trust chain,
but it is best to include all the required certificates directly in
$<a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a>. </p>
<p> Specify "<a href="postconf.5.html#smtp_tls_CAfile">smtp_tls_CAfile</a> = /path/to/system_CA_file" to use
ONLY the system-supplied default Certification Authority certificates.
</p>
<p> Specify "<a href="postconf.5.html#tls_append_default_CA">tls_append_default_CA</a> = no" to prevent Postfix from
appending the system-supplied default CAs and trusting third-party
certificates. </p>
<p> Example: </p>
<pre>
<a href="postconf.5.html#smtp_tls_CAfile">smtp_tls_CAfile</a> = /etc/postfix/CAcert.pem
</pre>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtp_tls_CApath">smtp_tls_CApath</a>
(default: empty)</b></DT><DD>
<p> Directory with PEM format Certification Authority certificates
that the Postfix SMTP client uses to verify a remote SMTP server
certificate. Don't forget to create the necessary "hash" links
with, for example, "$OPENSSL_HOME/bin/c_rehash /etc/postfix/certs".
</p>
<p> To use this option in chroot mode, this directory (or a copy)
must be inside the chroot jail. </p>
<p> Specify "<a href="postconf.5.html#smtp_tls_CApath">smtp_tls_CApath</a> = /path/to/system_CA_directory" to
use ONLY the system-supplied default Certification Authority certificates.
</p>
<p> Specify "<a href="postconf.5.html#tls_append_default_CA">tls_append_default_CA</a> = no" to prevent Postfix from
appending the system-supplied default CAs and trusting third-party
certificates. </p>
<p> Example: </p>
<pre>
<a href="postconf.5.html#smtp_tls_CApath">smtp_tls_CApath</a> = /etc/postfix/certs
</pre>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtp_tls_block_early_mail_reply">smtp_tls_block_early_mail_reply</a>
(default: no)</b></DT><DD>
<p> Try to detect a mail hijacking attack based on a TLS protocol
vulnerability (CVE-2009-3555), where an attacker prepends malicious
HELO, MAIL, RCPT, DATA commands to a Postfix SMTP client TLS session.
The attack would succeed with non-Postfix SMTP servers that reply
to the malicious HELO, MAIL, RCPT, DATA commands after negotiating
the Postfix SMTP client TLS session. </p>
<p> This feature is available in Postfix 2.7. </p>
</DD>
<DT><b><a name="smtp_tls_cert_file">smtp_tls_cert_file</a>
(default: empty)</b></DT><DD>
<p> File with the Postfix SMTP client RSA certificate in PEM format.
This file may also contain the Postfix SMTP client private RSA key,
and these may be the same as the Postfix SMTP server RSA certificate and key
file. </p>
<p> Do not configure client certificates unless you <b>must</b> present
client TLS certificates to one or more servers. Client certificates are
not usually needed, and can cause problems in configurations that work
well without them. The recommended setting is to let the defaults stand: </p>
<blockquote>
<pre>
<a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a> =
<a href="postconf.5.html#smtp_tls_key_file">smtp_tls_key_file</a> =
<a href="postconf.5.html#smtp_tls_dcert_file">smtp_tls_dcert_file</a> =
<a href="postconf.5.html#smtp_tls_dkey_file">smtp_tls_dkey_file</a> =
<a href="postconf.5.html#smtp_tls_eccert_file">smtp_tls_eccert_file</a> =
<a href="postconf.5.html#smtp_tls_eckey_file">smtp_tls_eckey_file</a> =
</pre>
</blockquote>
<p> The best way to use the default settings is to comment out the above
parameters in <a href="postconf.5.html">main.cf</a> if present. </p>
<p> To enable remote SMTP servers to verify the Postfix SMTP client
certificate, the issuing CA certificates must be made available to the
server. You should include the required certificates in the client
certificate file, the client certificate first, then the issuing
CA(s) (bottom-up order). </p>
<p> Example: the certificate for "client.example.com" was issued by
"intermediate CA" which itself has a certificate issued by "root CA".
Create the client.pem file with "cat client_cert.pem intermediate_CA.pem
root_CA.pem > client.pem". </p>
<p> If you also want to verify remote SMTP server certificates issued by
these CAs, you can add the CA certificates to the <a href="postconf.5.html#smtp_tls_CAfile">smtp_tls_CAfile</a>, in
which case it is not necessary to have them in the <a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a>,
<a href="postconf.5.html#smtp_tls_dcert_file">smtp_tls_dcert_file</a> or <a href="postconf.5.html#smtp_tls_eccert_file">smtp_tls_eccert_file</a>. </p>
<p> A certificate supplied here must be usable as an SSL client certificate
and hence pass the "openssl verify -purpose sslclient ..." test. </p>
<p> Example: </p>
<pre>
<a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a> = /etc/postfix/client.pem
</pre>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtp_tls_cipherlist">smtp_tls_cipherlist</a>
(default: empty)</b></DT><DD>
<p> Obsolete Postfix < 2.3 control for the Postfix SMTP client TLS
cipher list. As this feature applies to all TLS security levels, it is easy
to create interoperability problems by choosing a non-default cipher
list. Do not use a non-default TLS cipher list on hosts that deliver email
to the public Internet: you will be unable to send email to servers that
only support the ciphers you exclude. Using a restricted cipher list
may be more appropriate for an internal MTA, where one can exert some
control over the TLS software and settings of the peer servers. </p>
<p> <b>Note:</b> do not use "" quotes around the parameter value. </p>
<p> This feature is available in Postfix version 2.2. It is not used with
Postfix 2.3 and later; use <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> instead. </p>
</DD>
<DT><b><a name="smtp_tls_ciphers">smtp_tls_ciphers</a>
(default: medium)</b></DT><DD>
<p> The minimum TLS cipher grade that the Postfix SMTP client
will use with opportunistic TLS encryption. Cipher types listed in
<a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> are excluded from the base definition of
the selected cipher grade. The default value is "medium" for
Postfix releases after the middle of 2015, "export" for older
releases. </p>
<p> When TLS is mandatory the cipher grade is chosen via the
<a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> configuration parameter, see there for syntax
details. See <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> for information on how to configure
ciphers on a per-destination basis. </p>
<p> This feature is available in Postfix 2.6 and later. With earlier Postfix
releases only the <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> parameter is implemented,
and opportunistic TLS always uses "export" or better (i.e. all) ciphers. </p>
</DD>
<DT><b><a name="smtp_tls_dane_insecure_mx_policy">smtp_tls_dane_insecure_mx_policy</a>
(default: dane)</b></DT><DD>
<p> The TLS policy for MX hosts with "secure" TLSA records when the
nexthop destination security level is <b>dane</b>, but the MX
record was found via an "insecure" MX lookup. The choices are:
</p>
<dl>
<dt><b>may</b></dt>
<dd> The TLSA records will be ignored and TLS will be optional. If
the MX host does not appear to support STARTTLS, or the STARTTLS
handshake fails, mail may be sent in the clear. </dd>
<dt><b>encrypt</b></dt>
<dd> The TLSA records will signal a requirement to use TLS. While
TLS encryption will be required, authentication will not be performed.
</dd>
<dt><b>dane</b> (default)</dt>
<dd>The TLSA records will be used just as with "secure" MX records.
TLS encryption will be required, and, if at least one of the TLSA
records is "usable", authentication will be required. When
authentication succeeds, it will be logged only as "Trusted", not
"Verified", because the MX host name could have been forged. </dd>
</dl>
<p> Though with "insecure" MX records an active attacker can
compromise SMTP transport security by returning forged MX records,
such attacks are "tamper-evident" since any forged MX hostnames
will be recorded in the mail logs. Attackers who place a high value
staying hidden may be deterred from forging MX records. </p>
<p>
This feature is available in Postfix 3.1 and later. The <b>may</b>
policy is backwards-compatible with earlier Postfix versions.
</p>
</DD>
<DT><b><a name="smtp_tls_dcert_file">smtp_tls_dcert_file</a>
(default: empty)</b></DT><DD>
<p> File with the Postfix SMTP client DSA certificate in PEM format.
This file may also contain the Postfix SMTP client private DSA key. </p>
<p> See the discussion under <a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a> for more details.
</p>
<p> Example: </p>
<pre>
<a href="postconf.5.html#smtp_tls_dcert_file">smtp_tls_dcert_file</a> = /etc/postfix/client-dsa.pem
</pre>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtp_tls_dkey_file">smtp_tls_dkey_file</a>
(default: $<a href="postconf.5.html#smtp_tls_dcert_file">smtp_tls_dcert_file</a>)</b></DT><DD>
<p> File with the Postfix SMTP client DSA private key in PEM format.
This file may be combined with the Postfix SMTP client DSA certificate
file specified with $<a href="postconf.5.html#smtp_tls_dcert_file">smtp_tls_dcert_file</a>. </p>
<p> The private key must be accessible without a pass-phrase, i.e. it
must not be encrypted. File permissions should grant read-only
access to the system superuser account ("root"), and no access
to anyone else. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtp_tls_eccert_file">smtp_tls_eccert_file</a>
(default: empty)</b></DT><DD>
<p> File with the Postfix SMTP client ECDSA certificate in PEM format.
This file may also contain the Postfix SMTP client ECDSA private key. </p>
<p> See the discussion under <a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a> for more details.
</p>
<p> Example: </p>
<pre>
<a href="postconf.5.html#smtp_tls_eccert_file">smtp_tls_eccert_file</a> = /etc/postfix/ecdsa-ccert.pem
</pre>
<p> This feature is available in Postfix 2.6 and later, when Postfix is
compiled and linked with OpenSSL 1.0.0 or later. </p>
</DD>
<DT><b><a name="smtp_tls_eckey_file">smtp_tls_eckey_file</a>
(default: $<a href="postconf.5.html#smtp_tls_eccert_file">smtp_tls_eccert_file</a>)</b></DT><DD>
<p> File with the Postfix SMTP client ECDSA private key in PEM format.
This file may be combined with the Postfix SMTP client ECDSA
certificate file specified with $<a href="postconf.5.html#smtp_tls_eccert_file">smtp_tls_eccert_file</a>. </p>
<p> The private key must be accessible without a pass-phrase, i.e. it
must not be encrypted. File permissions should grant read-only
access to the system superuser account ("root"), and no access
to anyone else. </p>
<p> This feature is available in Postfix 2.6 and later, when Postfix is
compiled and linked with OpenSSL 1.0.0 or later. </p>
</DD>
<DT><b><a name="smtp_tls_enforce_peername">smtp_tls_enforce_peername</a>
(default: yes)</b></DT><DD>
<p> With mandatory TLS encryption, require that the remote SMTP
server hostname matches the information in the remote SMTP server
certificate. As of <a href="http://tools.ietf.org/html/rfc2487">RFC 2487</a> the requirements for hostname checking
for MTA clients are not specified. </p>
<p> This option can be set to "no" to disable strict peer name
checking. This setting has no effect on sessions that are controlled
via the <a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> table. </p>
<p> Disabling the hostname verification can make sense in closed
environment where special CAs are created. If not used carefully,
this option opens the danger of a "man-in-the-middle" attack (the
CommonName of this attacker will be logged). </p>
<p> This feature is available in Postfix 2.2 and later. With
Postfix 2.3 and later use <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> instead. </p>
</DD>
<DT><b><a name="smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a>
(default: empty)</b></DT><DD>
<p> List of ciphers or cipher types to exclude from the Postfix
SMTP client cipher
list at all TLS security levels. This is not an OpenSSL cipherlist, it is
a simple list separated by whitespace and/or commas. The elements are a
single cipher, or one or more "+" separated cipher properties, in which
case only ciphers matching <b>all</b> the properties are excluded. </p>
<p> Examples (some of these will cause problems): </p>
<blockquote>
<pre>
<a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> = aNULL
<a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> = MD5, DES
<a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> = DES+MD5
<a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> = AES256-SHA, DES-CBC3-MD5
<a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> = kEDH+aRSA
</pre>
</blockquote>
<p> The first setting, disables anonymous ciphers. The next setting
disables ciphers that use the MD5 digest algorithm or the (single) DES
encryption algorithm. The next setting disables ciphers that use MD5 and
DES together. The next setting disables the two ciphers "AES256-SHA"
and "DES-CBC3-MD5". The last setting disables ciphers that use "EDH"
key exchange with RSA authentication. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="smtp_tls_fingerprint_cert_match">smtp_tls_fingerprint_cert_match</a>
(default: empty)</b></DT><DD>
<p> List of acceptable remote SMTP server certificate fingerprints for
the "fingerprint" TLS security level (<b><a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a></b> =
fingerprint). At this security level, Certification Authorities are not
used, and certificate expiration times are ignored. Instead, server
certificates are verified directly via their certificate fingerprint
or public key fingerprint (Postfix 2.9 and later). The fingerprint
is a message digest of the server certificate (or public key). The
digest algorithm is selected via the <b><a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a></b>
parameter. </p>
<p> When an <b><a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a></b> table entry specifies the
"fingerprint" security level, any "match" attributes in that entry specify
the list of valid fingerprints for the corresponding destination. Multiple
fingerprints can be combined with a "|" delimiter in a single match
attribute, or multiple match attributes can be employed. </p>
<p> Example: Certificate fingerprint verification with internal mailhub.
Two matching fingerprints are listed. The <a href="postconf.5.html#relayhost">relayhost</a> may be multiple
physical hosts behind a load-balancer, each with its own private/public
key and self-signed certificate. Alternatively, a single <a href="postconf.5.html#relayhost">relayhost</a> may
be in the process of switching from one set of private/public keys to
another, and both keys are trusted just prior to the transition. </p>
<blockquote>
<pre>
<a href="postconf.5.html#relayhost">relayhost</a> = [mailhub.example.com]
<a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = fingerprint
<a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a> = md5
<a href="postconf.5.html#smtp_tls_fingerprint_cert_match">smtp_tls_fingerprint_cert_match</a> =
3D:95:34:51:24:66:33:B9:D2:40:99:C0:C1:17:0B:D1
EC:3B:2D:B0:5B:B1:FB:6D:20:A3:9D:72:F6:8D:12:35
</pre>
</blockquote>
<p> Example: Certificate fingerprint verification with selected destinations.
As in the example above, we show two matching fingerprints: </p>
<blockquote>
<pre>
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
<a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> = <a href="DATABASE_README.html#types">hash</a>:/etc/postfix/tls_policy
<a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a> = md5
</pre>
</blockquote>
<blockquote>
<pre>
/etc/postfix/tls_policy:
example.com fingerprint
match=3D:95:34:51:24:66:33:B9:D2:40:99:C0:C1:17:0B:D1
match=EC:3B:2D:B0:5B:B1:FB:6D:20:A3:9D:72:F6:8D:12:35
</pre>
</blockquote>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a>
(default: md5)</b></DT><DD>
<p> The message digest algorithm used to construct remote SMTP server
certificate fingerprints. At the "fingerprint" TLS security level
(<b><a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a></b> = fingerprint), the server certificate is
verified by directly matching its certificate fingerprint or its public
key fingerprint (Postfix 2.9 and later). The fingerprint is the
message digest of the server certificate (or its public key)
using the selected
algorithm. With a digest algorithm resistant to "second pre-image"
attacks, it is not feasible to create a new public key and a matching
certificate (or public/private key-pair) that has the same fingerprint. </p>
<p> The default algorithm is <b>md5</b>; this is consistent with
the backwards compatible setting of the digest used to verify client
certificates in the SMTP server. </p>
<p> The best practice algorithm is now <b>sha1</b>. Recent advances in hash
function cryptanalysis have led to md5 being deprecated in favor of sha1.
However, as long as there are no known "second pre-image" attacks
against md5, its use in this context can still be considered safe.
</p>
<p> While additional digest algorithms are often available with OpenSSL's
libcrypto, only those used by libssl in SSL cipher suites are available to
Postfix. For now this means just md5 or sha1. </p>
<p> To find the fingerprint of a specific certificate file, with a
specific digest algorithm, run:
</p>
<blockquote>
<pre>
$ openssl x509 -noout -fingerprint -<i>digest</i> -in <i>certfile</i>.pem
</pre>
</blockquote>
<p> The text to the right of "=" sign is the desired fingerprint.
For example: </p>
<blockquote>
<pre>
$ openssl x509 -noout -fingerprint -sha1 -in cert.pem
SHA1 Fingerprint=D4:6A:AB:19:24:79:F8:32:BB:A6:CB:66:82:C0:8E:9B:EE:29:A8:1A
</pre>
</blockquote>
<p> To extract the public key fingerprint from an X.509 certificate,
you need to extract the public key from the certificate and compute
the appropriate digest of its DER (ASN.1) encoding. With OpenSSL
the "-pubkey" option of the "x509" command extracts the public
key always in "PEM" format. We pipe the result to another OpenSSL
command that converts the key to DER and then to the "dgst" command
to compute the fingerprint. </p>
<p> The actual command to transform the key to DER format depends
on the version of OpenSSL used. With OpenSSL 1.0.0 and later, the
"pkey" command supports all key types. With OpenSSL 0.9.8 and
earlier, the key type is always RSA (nobody uses DSA, and EC
keys are not fully supported by 0.9.8), so the "rsa" command is
used. </p>
<blockquote>
<pre>
# OpenSSL 1.0 with all certificates and SHA-1 fingerprints.
$ openssl x509 -in cert.pem -noout -pubkey |
openssl pkey -pubin -outform DER |
openssl dgst -sha1 -c
(stdin)= 64:3f:1f:f6:e5:1e:d4:2a:56:8b:fc:09:1a:61:98:b5:bc:7c:60:58
</pre>
</blockquote>
<blockquote>
<pre>
# OpenSSL 0.9.8 with RSA certificates and MD5 fingerprints.
$ openssl x509 -in cert.pem -noout -pubkey |
openssl rsa -pubin -outform DER |
openssl dgst -md5 -c
(stdin)= f4:62:60:f6:12:8f:d5:8d:28:4d:13:a7:db:b2:ff:50
</pre>
</blockquote>
<p> The Postfix SMTP server and client log the peer (leaf) certificate
fingerprint and public key fingerprint when the TLS loglevel is 2 or
higher. </p>
<p> <b>Note:</b> Postfix 2.9.0–2.9.5 computed the public key
fingerprint incorrectly. To use public-key fingerprints, upgrade
to Postfix 2.9.6 or later. </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="smtp_tls_force_insecure_host_tlsa_lookup">smtp_tls_force_insecure_host_tlsa_lookup</a>
(default: no)</b></DT><DD>
<p> Lookup the associated DANE TLSA RRset even when a hostname is
not an alias and its address records lie in an unsigned zone. This
is unlikely to ever yield DNSSEC validated results, since child
zones of unsigned zones are also unsigned in the absence of DLV or
locally configured non-root trust-anchors. We anticipate that such
mechanisms will not be used for just the "_tcp" subdomain of a host.
Suppressing the TLSA RRset lookup reduces latency and avoids potential
interoperability problems with nameservers for unsigned zones that
are not prepared to handle the new TLSA RRset. </p>
<p> This feature is available in Postfix 2.11. </p>
</DD>
<DT><b><a name="smtp_tls_key_file">smtp_tls_key_file</a>
(default: $<a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a>)</b></DT><DD>
<p> File with the Postfix SMTP client RSA private key in PEM format.
This file may be combined with the Postfix SMTP client RSA certificate
file specified with $<a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a>. </p>
<p> The private key must be accessible without a pass-phrase, i.e. it
must not be encrypted. File permissions should grant read-only
access to the system superuser account ("root"), and no access
to anyone else. </p>
<p> Example: </p>
<pre>
<a href="postconf.5.html#smtp_tls_key_file">smtp_tls_key_file</a> = $<a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a>
</pre>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtp_tls_loglevel">smtp_tls_loglevel</a>
(default: 0)</b></DT><DD>
<p> Enable additional Postfix SMTP client logging of TLS activity.
Each logging level also includes the information that is logged at
a lower logging level. </p>
<dl compact>
<dt> </dt> <dd> 0 Disable logging of TLS activity. </dd>
<dt> </dt> <dd> 1 Log only a summary message on TLS handshake completion
— no logging of remote SMTP server certificate trust-chain
verification errors if server certificate verification is not required.
With Postfix 2.8 and earlier, log the summary message and unconditionally
log trust-chain verification errors. </dd>
<dt> </dt> <dd> 2 Also log levels during TLS negotiation. </dd>
<dt> </dt> <dd> 3 Also log hexadecimal and ASCII dump of TLS negotiation
process. </dd>
<dt> </dt> <dd> 4 Also log hexadecimal and ASCII dump of complete
transmission after STARTTLS. </dd>
</dl>
<p> Do not use "<a href="postconf.5.html#smtp_tls_loglevel">smtp_tls_loglevel</a> = 2" or higher except in case of
problems. Use of loglevel 4 is strongly discouraged. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a>
(default: medium)</b></DT><DD>
<p> The minimum TLS cipher grade that the Postfix SMTP client will
use with
mandatory TLS encryption. The default value "medium" is suitable
for most destinations with which you may want to enforce TLS, and
is beyond the reach of today's cryptanalytic methods. See
<a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> for information on how to configure ciphers
on a per-destination basis. </p>
<p> The following cipher grades are supported: </p>
<dl>
<dt><b>export</b></dt>
<dd> Enable "EXPORT" grade or better OpenSSL ciphers. The underlying
cipherlist is specified via the <a href="postconf.5.html#tls_export_cipherlist">tls_export_cipherlist</a> configuration
parameter, which you are strongly encouraged to not change. This
choice is insecure and SHOULD NOT be used. </dd>
<dt><b>low</b></dt>
<dd> Enable "LOW" grade or better OpenSSL ciphers. The underlying
cipherlist is specified via the <a href="postconf.5.html#tls_low_cipherlist">tls_low_cipherlist</a> configuration
parameter, which you are strongly encouraged to not change. This
choice is insecure and SHOULD NOT be used. </dd>
<dt><b>medium</b></dt>
<dd> Enable "MEDIUM" grade or better OpenSSL ciphers.
The underlying cipherlist is specified via the <a href="postconf.5.html#tls_medium_cipherlist">tls_medium_cipherlist</a>
configuration parameter, which you are strongly encouraged to not change.
</dd>
<dt><b>high</b></dt>
<dd> Enable only "HIGH" grade OpenSSL ciphers. This setting may
be appropriate when all mandatory TLS destinations (e.g. when all
mail is routed to a suitably capable <a href="postconf.5.html#relayhost">relayhost</a>) support at least one
"HIGH" grade cipher. The underlying cipherlist is specified via the
<a href="postconf.5.html#tls_high_cipherlist">tls_high_cipherlist</a> configuration parameter, which you are strongly
encouraged to not change. </dd>
<dt><b>null</b></dt>
<dd> Enable only the "NULL" OpenSSL ciphers, these provide authentication
without encryption. This setting is only appropriate in the rare case
that all servers are prepared to use NULL ciphers (not normally enabled
in TLS servers). A plausible use-case is an LMTP server listening on a
UNIX-domain socket that is configured to support "NULL" ciphers. The
underlying cipherlist is specified via the <a href="postconf.5.html#tls_null_cipherlist">tls_null_cipherlist</a>
configuration parameter, which you are strongly encouraged to not
change. </dd>
</dl>
<p> The underlying cipherlists for grades other than "null" include
anonymous ciphers, but these are automatically filtered out if the
Postfix SMTP client is configured to verify server certificates.
You are very unlikely to need to take any steps to exclude anonymous
ciphers, they are excluded automatically as necessary. If you must
exclude anonymous ciphers at the "may" or "encrypt" security levels,
when the Postfix SMTP client does not need or use peer certificates, set
"<a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a> = aNULL". To exclude anonymous ciphers only when
TLS is enforced, set "<a href="postconf.5.html#smtp_tls_mandatory_exclude_ciphers">smtp_tls_mandatory_exclude_ciphers</a> = aNULL". </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="smtp_tls_mandatory_exclude_ciphers">smtp_tls_mandatory_exclude_ciphers</a>
(default: empty)</b></DT><DD>
<p> Additional list of ciphers or cipher types to exclude from the
Postfix SMTP client cipher list at mandatory TLS security levels. This list
works in addition to the exclusions listed with <a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a>
(see there for syntax details). </p>
<p> Starting with Postfix 2.6, the mandatory cipher exclusions can be
specified on a per-destination basis via the TLS policy "exclude"
attribute. See <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> for notes and examples. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a>
(default: !SSLv2, !SSLv3)</b></DT><DD>
<p> List of SSL/TLS protocols that the Postfix SMTP client will use with
mandatory TLS encryption. In <a href="postconf.5.html">main.cf</a> the values are separated by
whitespace, commas or colons. In the policy table "protocols" attribute
(see <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a>) the only valid separator is colon. An
empty value means allow all protocols. The valid protocol names, (see
<b>SSL_get_version(3)</b>), are "SSLv2", "SSLv3" and "TLSv1". The
default value is "!SSLv2, !SSLv3" for Postfix releases after the
middle of 2015, "!SSLv2" for older releases. </p>
<p> With Postfix ≥ 2.5 the parameter syntax was expanded to support
protocol exclusions. One can explicitly exclude "SSLv2" by setting
"<a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> = !SSLv2". To exclude both "SSLv2" and
"SSLv3" set "<a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> = !SSLv2, !SSLv3". Listing
the protocols to include, rather than protocols to exclude, is
supported, but not recommended. The exclusion form more closely
matches the underlying OpenSSL interface semantics.
</p>
<p> The range of protocols advertised by an SSL/TLS client must be
contiguous. When a protocol version is enabled, disabling any
higher version implicitly disables all versions above that higher
version. Thus, for example: </p>
<blockquote>
<pre>
<a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> = !SSLv2, !TLSv1
</pre>
</blockquote>
<p> also disables any protocols version higher than TLSv1 leaving
only "SSLv3" enabled. </p>
<p> Note: As of OpenSSL 1.0.1 two new protocols are defined, "TLSv1.1"
and "TLSv1.2". When Postfix ≤ 2.5 is linked against OpenSSL 1.0.1
or later, these, or any other new protocol versions, cannot be
disabled except by also disabling "TLSv1" (typically leaving just
"SSLv3"). The latest patch levels of Postfix ≥ 2.6, and all
versions of Postfix ≥ 2.10 can explicitly disable support for
"TLSv1.1" or "TLSv1.2". </p>
<p> At the <a href="TLS_README.html#client_tls_dane">dane</a> and
<a href="TLS_README.html#client_tls_dane">dane-only</a> security
levels, when usable TLSA records are obtained for the remote SMTP
server, the Postfix SMTP client is obligated to include the SNI TLS
extension in its SSL client hello message. This may help the remote
SMTP server live up to its promise to provide a certificate that
matches its TLSA records. Since TLS extensions require TLS 1.0 or
later, the Postfix SMTP client must disable "SSLv2" and "SSLv3" when
SNI is required. If you use "dane" or "dane-only" do not disable
TLSv1, except perhaps via the policy table for destinations which
you are sure will support "TLSv1.1" or "TLSv1.2". </p>
<p> See the documentation of the <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> parameter and
<a href="TLS_README.html">TLS_README</a> for more information about security levels. </p>
<p> Example: </p>
<pre>
# Preferred syntax with Postfix ≥ 2.5:
<a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> = !SSLv2, !SSLv3
# Legacy syntax:
<a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> = TLSv1
</pre>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="smtp_tls_note_starttls_offer">smtp_tls_note_starttls_offer</a>
(default: no)</b></DT><DD>
<p> Log the hostname of a remote SMTP server that offers STARTTLS,
when TLS is not already enabled for that server. </p>
<p> The logfile record looks like: </p>
<pre>
postfix/smtp[pid]: Host offered STARTTLS: [name.of.host]
</pre>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtp_tls_per_site">smtp_tls_per_site</a>
(default: empty)</b></DT><DD>
<p> Optional lookup tables with the Postfix SMTP client TLS usage
policy by next-hop destination and by remote SMTP server hostname.
When both lookups succeed, the more specific per-site policy (NONE,
MUST, etc) overrides the less specific one (MAY), and the more secure
per-site policy (MUST, etc) overrides the less secure one (NONE).
With Postfix 2.3 and later <a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> is strongly discouraged:
use <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> instead. </p>
<p> Use of the bare hostname as the per-site table lookup key is
discouraged. Always use the full destination nexthop (enclosed in
[] with a possible ":port" suffix). A recipient domain or MX-enabled
transport next-hop with no port suffix may look like a bare hostname,
but is still a suitable <i>destination</i>. </p>
<p> Specify a next-hop destination or server hostname on the left-hand
side; no wildcards are allowed. The next-hop destination is either
the recipient domain, or the destination specified with a <a href="transport.5.html">transport(5)</a>
table, the <a href="postconf.5.html#relayhost">relayhost</a> parameter, or the <a href="postconf.5.html#relay_transport">relay_transport</a> parameter.
On the right hand side specify one of the following keywords: </p>
<dl>
<dt> NONE </dt> <dd> Don't use TLS at all. This overrides a less
specific <b>MAY</b> lookup result from the alternate host or next-hop
lookup key, and overrides the global <a href="postconf.5.html#smtp_use_tls">smtp_use_tls</a>, <a href="postconf.5.html#smtp_enforce_tls">smtp_enforce_tls</a>,
and <a href="postconf.5.html#smtp_tls_enforce_peername">smtp_tls_enforce_peername</a> settings. </dd>
<dt> MAY </dt> <dd> Try to use TLS if the server announces support,
otherwise use the unencrypted connection. This has less precedence
than a more specific result (including <b>NONE</b>) from the alternate
host or next-hop lookup key, and has less precedence than the more
specific global "<a href="postconf.5.html#smtp_enforce_tls">smtp_enforce_tls</a> = yes" or "<a href="postconf.5.html#smtp_tls_enforce_peername">smtp_tls_enforce_peername</a>
= yes". </dd>
<dt> MUST_NOPEERMATCH </dt> <dd> Require TLS encryption, but do not
require that the remote SMTP server hostname matches the information
in the remote SMTP server certificate, or that the server certificate
was issued by a trusted CA. This overrides a less secure <b>NONE</b>
or a less specific <b>MAY</b> lookup result from the alternate host
or next-hop lookup key, and overrides the global <a href="postconf.5.html#smtp_use_tls">smtp_use_tls</a>,
<a href="postconf.5.html#smtp_enforce_tls">smtp_enforce_tls</a> and <a href="postconf.5.html#smtp_tls_enforce_peername">smtp_tls_enforce_peername</a> settings. </dd>
<dt> MUST </dt> <dd> Require TLS encryption, require that the remote
SMTP server hostname matches the information in the remote SMTP
server certificate, and require that the remote SMTP server certificate
was issued by a trusted CA. This overrides a less secure <b>NONE</b>
and <b>MUST_NOPEERMATCH</b> or a less specific <b>MAY</b> lookup
result from the alternate host or next-hop lookup key, and overrides
the global <a href="postconf.5.html#smtp_use_tls">smtp_use_tls</a>, <a href="postconf.5.html#smtp_enforce_tls">smtp_enforce_tls</a> and <a href="postconf.5.html#smtp_tls_enforce_peername">smtp_tls_enforce_peername</a>
settings. </dd>
</dl>
<p> The above keywords correspond to the "none", "may", "encrypt" and
"verify" security levels for the new <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> parameter
introduced in Postfix 2.3. Starting with Postfix 2.3, and independently
of how the policy is specified, the <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> and
<a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> parameters apply when TLS encryption
is mandatory. Connections for which encryption is optional typically
enable all "export" grade and better ciphers (see <a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a>
and <a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a>). </p>
<p> As long as no secure DNS lookup mechanism is available, false
hostnames in MX or CNAME responses can change the server hostname
that Postfix uses for TLS policy lookup and server certificate
verification. Even with a perfect match between the server hostname and
the server certificate, there is no guarantee that Postfix is connected
to the right server. See <a href="TLS_README.html">TLS_README</a> (Closing a DNS loophole with obsolete
per-site TLS policies) for a possible work-around. </p>
<p> This feature is available in Postfix 2.2 and later. With
Postfix 2.3 and later use <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> instead. </p>
</DD>
<DT><b><a name="smtp_tls_policy_maps">smtp_tls_policy_maps</a>
(default: empty)</b></DT><DD>
<p> Optional lookup tables with the Postfix SMTP client TLS security
policy by next-hop destination; when a non-empty value is specified,
this overrides the obsolete <a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> parameter. See
<a href="TLS_README.html">TLS_README</a> for a more detailed discussion of TLS security levels.
</p>
<p>
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found.
</p>
<p> The TLS policy table is indexed by the full next-hop destination,
which is either the recipient domain, or the verbatim next-hop
specified in the transport table, $<a href="postconf.5.html#local_transport">local_transport</a>, $<a href="postconf.5.html#virtual_transport">virtual_transport</a>,
$<a href="postconf.5.html#relay_transport">relay_transport</a> or $<a href="postconf.5.html#default_transport">default_transport</a>. This includes any enclosing
square brackets and any non-default destination server port suffix. The
LMTP socket type prefix (inet: or unix:) is not included in the lookup
key. </p>
<p> Only the next-hop domain, or $<a href="postconf.5.html#myhostname">myhostname</a> with LMTP over UNIX-domain
sockets, is used as the nexthop name for certificate verification. The
port and any enclosing square brackets are used in the table lookup key,
but are not used for server name verification. </p>
<p> When the lookup key is a domain name without enclosing square brackets
or any <i>:port</i> suffix (typically the recipient domain), and the full
domain is not found in the table, just as with the <a href="transport.5.html">transport(5)</a> table,
the parent domain starting with a leading "." is matched recursively. This
allows one to specify a security policy for a recipient domain and all
its sub-domains. </p>
<p> The lookup result is a security level, followed by an optional list
of whitespace and/or comma separated name=value attributes that override
related <a href="postconf.5.html">main.cf</a> settings. The TLS security levels in order of increasing
security are: </p>
<dl>
<dt><b><a href="TLS_README.html#client_tls_none">none</a></b></dt>
<dd>No TLS. No additional attributes are supported at this level. </dd>
<dt><b><a href="TLS_README.html#client_tls_may">may</a></b></dt>
<dd>Opportunistic TLS. Since sending in the clear is acceptable,
demanding stronger than default TLS security merely reduces
interoperability. The optional "ciphers", "exclude" and "protocols"
attributes (available for opportunistic TLS with Postfix ≥ 2.6)
override the "<a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a>", "<a href="postconf.5.html#smtp_tls_exclude_ciphers">smtp_tls_exclude_ciphers</a>" and
"<a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a>" configuration parameters. When opportunistic TLS
handshakes fail, Postfix retries the connection with TLS disabled.
This allows mail delivery to sites with non-interoperable TLS
implementations.</dd>
<dt><b><a href="TLS_README.html#client_tls_encrypt">encrypt</a></b></dt>
<dd>Mandatory TLS encryption. At this level
and higher, the optional "protocols" attribute overrides the <a href="postconf.5.html">main.cf</a>
<a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> parameter, the optional "ciphers" attribute
overrides the <a href="postconf.5.html">main.cf</a> <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> parameter, and the
optional "exclude" attribute (Postfix ≥ 2.6) overrides the <a href="postconf.5.html">main.cf</a>
<a href="postconf.5.html#smtp_tls_mandatory_exclude_ciphers">smtp_tls_mandatory_exclude_ciphers</a> parameter. In the policy table,
multiple protocols or excluded ciphers must be separated by colons,
as attribute values may not contain whitespace or commas. </dd>
<dt><b><a href="TLS_README.html#client_tls_dane">dane</a></b></dt>
<dd>Opportunistic DANE TLS. The TLS policy for the destination is
obtained via TLSA records in DNSSEC. If no TLSA records are found,
the effective security level used is <a
href="TLS_README.html#client_tls_may">may</a>. If TLSA records are
found, but none are usable, the effective security level is <a
href="TLS_README.html#client_tls_encrypt">encrypt</a>. When usable
TLSA records are obtained for the remote SMTP server, the
server certificate must match the TLSA records. <a href="http://tools.ietf.org/html/rfc7672">RFC 7672</a> (DANE)
TLS authentication and DNSSEC support is available with Postfix
2.11 and later. </dd>
<dt><b><a href="TLS_README.html#client_tls_dane">dane-only</a></b></dt>
<dd>Mandatory DANE TLS. The TLS policy for the destination is
obtained via TLSA records in DNSSEC. If no TLSA records are found,
or none are usable, no connection is made to the server. When
usable TLSA records are obtained for the remote SMTP server, the
server certificate must match the TLSA records. <a href="http://tools.ietf.org/html/rfc7672">RFC 7672</a> (DANE) TLS
authentication and DNSSEC support is available with Postfix 2.11
and later. </dd>
<dt><b><a href="TLS_README.html#client_tls_fprint">fingerprint</a></b></dt>
<dd>Certificate fingerprint
verification. Available with Postfix 2.5 and later. At this security
level, there are no trusted Certification Authorities. The certificate
trust chain, expiration date, ... are not checked. Instead,
the optional <b>match</b> attribute, or else the <a href="postconf.5.html">main.cf</a>
<b><a href="postconf.5.html#smtp_tls_fingerprint_cert_match">smtp_tls_fingerprint_cert_match</a></b> parameter, lists the certificate
fingerprints or the public key fingerprint (Postfix 2.9 and later)
of the valid server certificate. The digest
algorithm used to calculate the fingerprint is selected by the
<b><a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a></b> parameter. Multiple fingerprints can
be combined with a "|" delimiter in a single match attribute, or multiple
match attributes can be employed. The ":" character is not used as a
delimiter as it occurs between each pair of fingerprint (hexadecimal)
digits. </dd>
<dt><b><a href="TLS_README.html#client_tls_verify">verify</a></b></dt>
<dd>Mandatory TLS verification. At this security
level, DNS MX lookups are trusted to be secure enough, and the name
verified in the server certificate is usually obtained indirectly via
unauthenticated DNS MX lookups. The optional "match" attribute overrides
the <a href="postconf.5.html">main.cf</a> <a href="postconf.5.html#smtp_tls_verify_cert_match">smtp_tls_verify_cert_match</a> parameter. In the policy table,
multiple match patterns and strategies must be separated by colons.
In practice explicit control over matching is more common with the
"secure" policy, described below. </dd>
<dt><b><a href="TLS_README.html#client_tls_secure">secure</a></b></dt>
<dd>Secure-channel TLS. At this security level, DNS
MX lookups, though potentially used to determine the candidate next-hop
gateway IP addresses, are <b>not</b> trusted to be secure enough for TLS
peername verification. Instead, the default name verified in the server
certificate is obtained directly from the next-hop, or is explicitly
specified via the optional <b>match</b> attribute which overrides the
<a href="postconf.5.html">main.cf</a> <a href="postconf.5.html#smtp_tls_secure_cert_match">smtp_tls_secure_cert_match</a> parameter. In the policy table,
multiple match patterns and strategies must be separated by colons.
The match attribute is most useful when multiple domains are supported by
common server, the policy entries for additional domains specify matching
rules for the primary domain certificate. While transport table overrides
routing the secondary domains to the primary nexthop also allow secure
verification, they risk delivery to the wrong destination when domains
change hands or are re-assigned to new gateways. With the "match"
attribute approach, routing is not perturbed, and mail is deferred if
verification of a new MX host fails. </dd>
</dl>
<p>
Example:
</p>
<pre>
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
<a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a> = <a href="DATABASE_README.html#types">hash</a>:/etc/postfix/tls_policy
# Postfix 2.5 and later
<a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a> = md5
</pre>
<pre>
/etc/postfix/tls_policy:
example.edu none
example.mil may
example.gov encrypt protocols=TLSv1
example.com verify ciphers=high
example.net secure
.example.net secure match=.example.net:example.net
[mail.example.org]:587 secure match=nexthop
# Postfix 2.5 and later
[thumb.example.org] fingerprint
match=EC:3B:2D:B0:5B:B1:FB:6D:20:A3:9D:72:F6:8D:12:35
match=3D:95:34:51:24:66:33:B9:D2:40:99:C0:C1:17:0B:D1
</pre>
<p> <b>Note:</b> The <b>hostname</b> strategy if listed in a non-default
setting of <a href="postconf.5.html#smtp_tls_secure_cert_match">smtp_tls_secure_cert_match</a> or in the <b>match</b> attribute
in the policy table can render the <b>secure</b> level vulnerable to
DNS forgery. Do not use the <b>hostname</b> strategy for secure-channel
configurations in environments where DNS security is not assured. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="smtp_tls_protocols">smtp_tls_protocols</a>
(default: !SSLv2, !SSLv3)</b></DT><DD>
<p> List of TLS protocols that the Postfix SMTP client will exclude or
include with opportunistic TLS encryption. The default value is
"!SSLv2, !SSLv3" for Postfix releases after the middle of 2015,
"!SSLv2" for older releases. Before Postfix 2.6, the Postfix SMTP
client would use all protocols with opportunistic TLS. </p>
<p> In <a href="postconf.5.html">main.cf</a> the values are separated by whitespace, commas or
colons. In the policy table (see <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a>) the only valid
separator is colon. An empty value means allow all protocols. The valid
protocol names, (see <b>SSL_get_version(3)</b>), are "SSLv2", "SSLv3"
and "TLSv1". </p>
<p> The range of protocols advertised by an SSL/TLS client must be
contiguous. When a protocol version is enabled, disabling any
higher version implicitly disables all versions above that higher
version. Thus, for example: </p>
<blockquote>
<pre>
<a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> = !SSLv2, !TLSv1
</pre>
</blockquote>
<p> also disables any protocols version higher than TLSv1 leaving
only "SSLv3" enabled. </p>
<p> Note: As of OpenSSL 1.0.1 two new protocols are defined, "TLSv1.1"
and "TLSv1.2". The latest patch levels of Postfix ≥ 2.6, and all
versions of Postfix ≥ 2.10 can explicitly disable support for
"TLSv1.1" or "TLSv1.2"</p>
<p> To include a protocol list its name, to exclude it, prefix the name
with a "!" character. To exclude SSLv2 for opportunistic TLS set
"<a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> = !SSLv2". To exclude both "SSLv2" and "SSLv3" set
"<a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> = !SSLv2, !SSLv3". Explicitly listing the protocols to
include, rather than protocols to exclude, is supported, but not
recommended. The exclusion form more closely matches the underlying
OpenSSL interface semantics. </p>
<p> Example: </p>
<pre>
# TLSv1 or better:
<a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> = !SSLv2, !SSLv3
</pre>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="smtp_tls_scert_verifydepth">smtp_tls_scert_verifydepth</a>
(default: 9)</b></DT><DD>
<p> The verification depth for remote SMTP server certificates. A depth
of 1 is sufficient if the issuing CA is listed in a local CA file. </p>
<p> The default verification depth is 9 (the OpenSSL default) for
compatibility with earlier Postfix behavior. Prior to Postfix 2.5,
the default value was 5, but the limit was not actually enforced. If
you have set this to a lower non-default value, certificates with longer
trust chains may now fail to verify. Certificate chains with 1 or 2
CAs are common, deeper chains are more rare and any number between 5
and 9 should suffice in practice. You can choose a lower number if,
for example, you trust certificates directly signed by an issuing CA
but not any CAs it delegates to. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtp_tls_secure_cert_match">smtp_tls_secure_cert_match</a>
(default: nexthop, dot-nexthop)</b></DT><DD>
<p> How the Postfix SMTP client verifies the server certificate
peername for the "secure" TLS security level. In a "secure" TLS policy table
($<a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a>) entry the optional "match" attribute
overrides this <a href="postconf.5.html">main.cf</a> setting. </p>
<p> This parameter specifies one or more patterns or strategies separated
by commas, whitespace or colons. In the policy table the only valid
separator is the colon character. </p>
<p> For a description of the pattern and strategy syntax see the
<a href="postconf.5.html#smtp_tls_verify_cert_match">smtp_tls_verify_cert_match</a> parameter. The "hostname" strategy should
be avoided in this context, as in the absence of a secure global DNS, using
the results of MX lookups in certificate verification is not immune to active
(man-in-the-middle) attacks on DNS. </p>
<p>
Sample <a href="postconf.5.html">main.cf</a> setting:
</p>
<blockquote>
<pre>
<a href="postconf.5.html#smtp_tls_secure_cert_match">smtp_tls_secure_cert_match</a> = nexthop
</pre>
</blockquote>
<p>
Sample policy table override:
</p>
<blockquote>
<pre>
example.net secure match=example.com:.example.com
.example.net secure match=example.com:.example.com
</pre>
</blockquote>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="smtp_tls_security_level">smtp_tls_security_level</a>
(default: empty)</b></DT><DD>
<p> The default SMTP TLS security level for the Postfix SMTP client;
when a non-empty value is specified, this overrides the obsolete
parameters <a href="postconf.5.html#smtp_use_tls">smtp_use_tls</a>, <a href="postconf.5.html#smtp_enforce_tls">smtp_enforce_tls</a>, and <a href="postconf.5.html#smtp_tls_enforce_peername">smtp_tls_enforce_peername</a>.
</p>
<p> Specify one of the following security levels: </p>
<dl>
<dt><b><a href="TLS_README.html#client_tls_none">none</a></b></dt>
<dd> No TLS. TLS will not be used unless enabled for specific
destinations via <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a>. </dd>
<dt><b><a href="TLS_README.html#client_tls_may">may</a></b></dt>
<dd> Opportunistic TLS. Use TLS if this is supported by the remote
SMTP server, otherwise use plaintext. Since
sending in the clear is acceptable, demanding stronger than default TLS
security merely reduces interoperability.
The "<a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a>" and "<a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a>" (Postfix ≥ 2.6)
configuration parameters provide control over the protocols and
cipher grade used with opportunistic TLS. With earlier releases the
opportunistic TLS cipher grade is always "export" and no protocols
are disabled.
When TLS handshakes fail, the connection is retried with TLS disabled.
This allows mail delivery to sites with non-interoperable TLS
implementations. </dd>
<dt><b><a href="TLS_README.html#client_tls_encrypt">encrypt</a></b></dt>
<dd>Mandatory TLS encryption. Since a minimum
level of security is intended, it is reasonable to be specific about
sufficiently secure protocol versions and ciphers. At this security level
and higher, the <a href="postconf.5.html">main.cf</a> parameters <a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> and
<a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> specify the TLS protocols and minimum
cipher grade which the administrator considers secure enough for
mandatory encrypted sessions. This security level is not an appropriate
default for systems delivering mail to the Internet. </dd>
<dt><b><a href="TLS_README.html#client_tls_dane">dane</a></b></dt>
<dd>Opportunistic DANE TLS. At this security level, the TLS policy
for the destination is obtained via DNSSEC. For TLSA policy to be
in effect, the destination domain's containing DNS zone must be
signed and the Postfix SMTP client's operating system must be
configured to send its DNS queries to a recursive DNS nameserver
that is able to validate the signed records. Each MX host's DNS
zone should also be signed, and should publish DANE TLSA (<a href="http://tools.ietf.org/html/rfc7672">RFC 7672</a>)
records that specify how that MX host's TLS certificate is to be
verified. TLSA records do not preempt the normal SMTP MX host
selection algorithm, if some MX hosts support TLSA and others do
not, TLS security will vary from delivery to delivery. It is up
to the domain owner to configure their MX hosts and their DNS
sensibly. To configure the Postfix SMTP client for DNSSEC lookups
see the documentation for the <a href="postconf.5.html#smtp_dns_support_level">smtp_dns_support_level</a> <a href="postconf.5.html">main.cf</a>
parameter. When DNSSEC-validated TLSA records are not found the
effective tls security level is "may". When TLSA records are found,
but are all unusable the effective security level is "encrypt". For
purposes of protocol and cipher selection, the "dane" security level
is treated like a "mandatory" TLS security level, and weak ciphers
and protocols are disabled. Since DANE authenticates server
certificates the "aNULL" cipher-suites are transparently excluded
at this level, no need to configure this manually. <a href="http://tools.ietf.org/html/rfc7672">RFC 7672</a> (DANE)
TLS authentication is available with Postfix 2.11 and later. </dd>
<dt><b><a href="TLS_README.html#client_tls_dane">dane-only</a></b></dt>
<dd>Mandatory DANE TLS. This is just like "dane" above, but DANE
TLSA authentication is required. There is no fallback to "may" or
"encrypt" when TLSA records are missing or unusable. <a href="http://tools.ietf.org/html/rfc7672">RFC 7672</a>
(DANE) TLS authentication is available with Postfix 2.11 and later.
</dd>
<dt><b><a href="TLS_README.html#client_tls_fprint">fingerprint</a></b></dt>
<dd>Certificate fingerprint verification.
At this security level, there are no trusted Certification Authorities.
The certificate trust chain, expiration date, etc., are
not checked. Instead, the <b><a href="postconf.5.html#smtp_tls_fingerprint_cert_match">smtp_tls_fingerprint_cert_match</a></b>
parameter lists the certificate fingerprint or public key fingerprint
(Postfix 2.9 and later) of the valid server certificate. The digest
algorithm used to calculate the fingerprint is selected by the
<b><a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a></b> parameter. Available with Postfix
2.5 and later. </dd>
<dt><b><a href="TLS_README.html#client_tls_verify">verify</a></b></dt>
<dd>Mandatory TLS verification. At this security
level, DNS MX lookups are trusted to be secure enough, and the name
verified in the server certificate is usually obtained indirectly
via unauthenticated DNS MX lookups. The <a href="postconf.5.html#smtp_tls_verify_cert_match">smtp_tls_verify_cert_match</a>
parameter controls how the server name is verified. In practice explicit
control over matching is more common at the "secure" level, described
below. This security level is not an appropriate default for systems
delivering mail to the Internet. </dd>
<dt><b><a href="TLS_README.html#client_tls_secure">secure</a></b></dt>
<dd>Secure-channel TLS. At this security level,
DNS MX lookups, though potentially used to determine the candidate
next-hop gateway IP addresses, are <b>not</b> trusted to be secure enough
for TLS peername verification. Instead, the default name verified in
the server certificate is obtained from the next-hop domain as specified
in the <a href="postconf.5.html#smtp_tls_secure_cert_match">smtp_tls_secure_cert_match</a> configuration parameter. The default
matching rule is that a server certificate matches when its name is equal
to or is a sub-domain of the nexthop domain. This security level is not
an appropriate default for systems delivering mail to the Internet. </dd>
</dl>
<p>
Examples:
</p>
<pre>
# No TLS. Formerly: <a href="postconf.5.html#smtp_use_tls">smtp_use_tls</a>=no and <a href="postconf.5.html#smtp_enforce_tls">smtp_enforce_tls</a>=no.
<a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = none
</pre>
<pre>
# Opportunistic TLS.
<a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = may
# Postfix ≥ 2.6:
# Do not tweak opportunistic ciphers or protocol unless it is essential
# to do so (if a security vulnerability is found in the SSL library that
# can be mitigated by disabling a particular protocol or raising the
# cipher grade from "export" to "low" or "medium").
<a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a> = export
<a href="postconf.5.html#smtp_tls_protocols">smtp_tls_protocols</a> = !SSLv2, !SSLv3
</pre>
<pre>
# Mandatory (high-grade) TLS encryption.
<a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = encrypt
<a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> = high
</pre>
<pre>
# Mandatory TLS verification of hostname or nexthop domain.
<a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = verify
<a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> = high
<a href="postconf.5.html#smtp_tls_verify_cert_match">smtp_tls_verify_cert_match</a> = hostname, nexthop, dot-nexthop
</pre>
<pre>
# Secure channel TLS with exact nexthop name match.
<a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = secure
<a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> = TLSv1
<a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> = high
<a href="postconf.5.html#smtp_tls_secure_cert_match">smtp_tls_secure_cert_match</a> = nexthop
</pre>
<pre>
# Certificate fingerprint verification (Postfix ≥ 2.5).
# The CA-less "fingerprint" security level only scales to a limited
# number of destinations. As a global default rather than a per-site
# setting, this is practical when mail for all recipients is sent
# to a central mail hub.
<a href="postconf.5.html#relayhost">relayhost</a> = [mailhub.example.com]
<a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = fingerprint
<a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> = !SSLv2, !SSLv3
<a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> = high
<a href="postconf.5.html#smtp_tls_fingerprint_cert_match">smtp_tls_fingerprint_cert_match</a> =
3D:95:34:51:24:66:33:B9:D2:40:99:C0:C1:17:0B:D1
EC:3B:2D:B0:5B:B1:FB:6D:20:A3:9D:72:F6:8D:12:35
</pre>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="smtp_tls_session_cache_database">smtp_tls_session_cache_database</a>
(default: empty)</b></DT><DD>
<p> Name of the file containing the optional Postfix SMTP client
TLS session cache. Specify a database type that supports enumeration,
such as <b>btree</b> or <b>sdbm</b>; there is no need to support
concurrent access. The file is created if it does not exist. The <a href="smtp.8.html">smtp(8)</a>
daemon does not use this parameter directly, rather the cache is
implemented indirectly in the <a href="tlsmgr.8.html">tlsmgr(8)</a> daemon. This means that
per-smtp-instance <a href="master.5.html">master.cf</a> overrides of this parameter are not effective.
Note, that each of the cache databases supported by <a href="tlsmgr.8.html">tlsmgr(8)</a> daemon:
$<a href="postconf.5.html#smtpd_tls_session_cache_database">smtpd_tls_session_cache_database</a>, $<a href="postconf.5.html#smtp_tls_session_cache_database">smtp_tls_session_cache_database</a>
(and with Postfix 2.3 and later $<a href="postconf.5.html#lmtp_tls_session_cache_database">lmtp_tls_session_cache_database</a>), needs to
be stored separately. It is not at this time possible to store multiple
caches in a single database. </p>
<p> Note: <b>dbm</b> databases are not suitable. TLS
session objects are too large. </p>
<p> As of version 2.5, Postfix no longer uses root privileges when
opening this file. The file should now be stored under the Postfix-owned
<a href="postconf.5.html#data_directory">data_directory</a>. As a migration aid, an attempt to open the file
under a non-Postfix directory is redirected to the Postfix-owned
<a href="postconf.5.html#data_directory">data_directory</a>, and a warning is logged. </p>
<p> Example: </p>
<pre>
<a href="postconf.5.html#smtp_tls_session_cache_database">smtp_tls_session_cache_database</a> = <a href="DATABASE_README.html#types">btree</a>:/var/lib/postfix/smtp_scache
</pre>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtp_tls_session_cache_timeout">smtp_tls_session_cache_timeout</a>
(default: 3600s)</b></DT><DD>
<p> The expiration time of Postfix SMTP client TLS session cache
information. A cache cleanup is performed periodically
every $<a href="postconf.5.html#smtp_tls_session_cache_timeout">smtp_tls_session_cache_timeout</a> seconds. As with
$<a href="postconf.5.html#smtp_tls_session_cache_database">smtp_tls_session_cache_database</a>, this parameter is implemented in the
<a href="tlsmgr.8.html">tlsmgr(8)</a> daemon and therefore per-smtp-instance <a href="master.5.html">master.cf</a> overrides
are not possible. </p>
<p> As of Postfix 2.11 this setting cannot exceed 100 days. If set
≤ 0, session caching is disabled. If set to a positive value
less than 2 minutes, the minimum value of 2 minutes is used instead. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtp_tls_trust_anchor_file">smtp_tls_trust_anchor_file</a>
(default: empty)</b></DT><DD>
<p> Zero or more PEM-format files with trust-anchor certificates
and/or public keys. If the parameter is not empty the root CAs in
CAfile and CApath are no longer trusted. Rather, the Postfix SMTP
client will only trust certificate-chains signed by one of the
trust-anchors contained in the chosen files. The specified
trust-anchor certificates and public keys are not subject to
expiration, and need not be (self-signed) root CAs. They may, if
desired, be intermediate certificates. Therefore, these certificates
also may be found "in the middle" of the trust chain presented by
the remote SMTP server, and any untrusted issuing parent certificates
will be ignored. Specify a list of pathnames separated by comma
or whitespace. </p>
<p> Whether specified in <a href="postconf.5.html">main.cf</a>, or on a per-destination basis,
the trust-anchor PEM file must be accessible to the Postfix SMTP
client in the chroot jail if applicable. The trust-anchor file
should contain only certificates and public keys, no private key
material, and must be readable by the non-privileged $<a href="postconf.5.html#mail_owner">mail_owner</a>
user. This allows destinations to be bound to a set of specific
CAs or public keys without trusting the same CAs for all destinations.
</p>
<p> The <a href="postconf.5.html">main.cf</a> parameter supports single-purpose Postfix installations
that send mail to a fixed set of SMTP peers. At most sites, if
trust-anchor files are used at all, they will be specified on a
per-destination basis via the "tafile" attribute of the "verify"
and "secure" levels in <a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a>. </p>
<p> The underlying mechanism is in support of <a href="http://tools.ietf.org/html/rfc7672">RFC 7672</a> (DANE TLSA),
which defines mechanisms for an SMTP client MTA to securely determine
server TLS certificates via DNS. </p>
<p> If you want your trust anchors to be public keys, with OpenSSL
you can extract a single PEM public key from a PEM X.509 file
containing a single certificate, as follows: </p>
<blockquote>
<pre>
$ openssl x509 -in cert.pem -out ta-key.pem -noout -pubkey
</pre>
</blockquote>
<p> This feature is available in Postfix 2.11 and later. </p>
</DD>
<DT><b><a name="smtp_tls_verify_cert_match">smtp_tls_verify_cert_match</a>
(default: hostname)</b></DT><DD>
<p> How the Postfix SMTP client verifies the server certificate
peername for the
"verify" TLS security level. In a "verify" TLS policy table
($<a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a>) entry the optional "match" attribute
overrides this <a href="postconf.5.html">main.cf</a> setting. </p>
<p> This parameter specifies one or more patterns or strategies separated
by commas, whitespace or colons. In the policy table the only valid
separator is the colon character. </p>
<p> Patterns specify domain names, or domain name suffixes: </p>
<dl>
<dt><i>example.com</i></dt> <dd> Match the <i>example.com</i> domain,
i.e. one of the names the server certificate must be <i>example.com</i>,
upper and lower case distinctions are ignored. </dd>
<dt><i>.example.com</i></dt>
<dd> Match subdomains of the <i>example.com</i> domain, i.e. match
a name in the server certificate that consists of a non-zero number of
labels followed by a <i>.example.com</i> suffix. Case distinctions are
ignored.</dd>
</dl>
<p> Strategies specify a transformation from the next-hop domain
to the expected name in the server certificate: </p>
<dl>
<dt>nexthop</dt>
<dd> Match against the next-hop domain, which is either the recipient
domain, or the transport next-hop configured for the domain stripped of
any optional socket type prefix, enclosing square brackets and trailing
port. When MX lookups are not suppressed, this is the original nexthop
domain prior to the MX lookup, not the result of the MX lookup. For
LMTP delivery via UNIX-domain sockets, the verified next-hop name is
$<a href="postconf.5.html#myhostname">myhostname</a>. This strategy is suitable for use with the "secure"
policy. Case is ignored.</dd>
<dt>dot-nexthop</dt>
<dd> As above, but match server certificate names that are subdomains
of the next-hop domain. Case is ignored.</dd>
<dt>hostname</dt> <dd> Match against the hostname of the server, often
obtained via an unauthenticated DNS MX lookup. For LMTP delivery via
UNIX-domain sockets, the verified name is $<a href="postconf.5.html#myhostname">myhostname</a>. This matches
the verification strategy of the "MUST" keyword in the obsolete
<a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> table, and is suitable for use with the "verify"
security level. When the next-hop name is enclosed in square brackets
to suppress MX lookups, the "hostname" strategy is the same as the
"nexthop" strategy. Case is ignored.</dd>
</dl>
<p>
Sample <a href="postconf.5.html">main.cf</a> setting:
</p>
<pre>
<a href="postconf.5.html#smtp_tls_verify_cert_match">smtp_tls_verify_cert_match</a> = hostname, nexthop, dot-nexthop
</pre>
<p>
Sample policy table override:
</p>
<pre>
example.com verify match=hostname:nexthop
.example.com verify match=example.com:.example.com:hostname
</pre>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="smtp_tls_wrappermode">smtp_tls_wrappermode</a>
(default: no)</b></DT><DD>
<p> Request that the Postfix SMTP client connects using the
legacy SMTPS protocol instead of using the STARTTLS command. </p>
<p> This mode requires "<a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = encrypt" or
stronger. </p>
<p> Example: deliver all remote mail via a provider's server
"mail.example.com". </p>
<pre>
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
# Client-side SMTPS requires "encrypt" or stronger.
<a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> = encrypt
<a href="postconf.5.html#smtp_tls_wrappermode">smtp_tls_wrappermode</a> = yes
# The [] suppress MX lookups.
<a href="postconf.5.html#relayhost">relayhost</a> = [mail.example.com]:465
</pre>
<p> More examples are in <a href="TLS_README.html">TLS_README</a>, including examples for older
Postfix versions. </p>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="smtp_use_tls">smtp_use_tls</a>
(default: no)</b></DT><DD>
<p> Opportunistic mode: use TLS when a remote SMTP server announces
STARTTLS support, otherwise send the mail in the clear. Beware:
some SMTP servers offer STARTTLS even if it is not configured. With
Postfix < 2.3, if the TLS handshake fails, and no other server is
available, delivery is deferred and mail stays in the queue. If this
is a concern for you, use the <a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a> feature instead. </p>
<p> This feature is available in Postfix 2.2 and later. With
Postfix 2.3 and later use <a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a> instead. </p>
</DD>
<DT><b><a name="smtp_xforward_timeout">smtp_xforward_timeout</a>
(default: 300s)</b></DT><DD>
<p>
The Postfix SMTP client time limit for sending the XFORWARD command,
and for receiving the remote SMTP server response.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="smtpd_authorized_verp_clients">smtpd_authorized_verp_clients</a>
(default: $<a href="postconf.5.html#authorized_verp_clients">authorized_verp_clients</a>)</b></DT><DD>
<p> What remote SMTP clients are allowed to specify the XVERP command.
This command requests that mail be delivered one recipient at a
time with a per recipient return address. </p>
<p> By default, no clients are allowed to specify XVERP. </p>
<p> This parameter was renamed with Postfix version 2.1. The default value
is backwards compatible with Postfix version 2.0. </p>
<p> Specify a list of network/netmask patterns, separated by commas
and/or whitespace. The mask specifies the number of bits in the
network part of a host address. You can also specify hostnames or
.domain names (the initial dot causes the domain to match any name
below it), "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns. A "/file/name"
pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table
is matched when a table entry matches a lookup string (the lookup
result is ignored). Continue long lines by starting the next line
with whitespace. Specify "!pattern" to exclude an address or network
block from the list. The form "!/file/name" is supported only in
Postfix version 2.4 and later. </p>
<p> Note: IP version 6 address information must be specified inside
<tt>[]</tt> in the <a href="postconf.5.html#smtpd_authorized_verp_clients">smtpd_authorized_verp_clients</a> value, and in
files specified with "/file/name". IP version 6 addresses contain
the ":" character, and would otherwise be confused with a "<a href="DATABASE_README.html">type:table</a>"
pattern. </p>
</DD>
<DT><b><a name="smtpd_authorized_xclient_hosts">smtpd_authorized_xclient_hosts</a>
(default: empty)</b></DT><DD>
<p>
What remote SMTP clients are allowed to use the XCLIENT feature. This
command overrides remote SMTP client information that is used for access
control. Typical use is for SMTP-based content filters, fetchmail-like
programs, or SMTP server access rule testing. See the <a href="XCLIENT_README.html">XCLIENT_README</a>
document for details.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
<p>
By default, no clients are allowed to specify XCLIENT.
</p>
<p>
Specify a list of network/netmask patterns, separated by commas
and/or whitespace. The mask specifies the number of bits in the
network part of a host address. You can also specify hostnames or
.domain names (the initial dot causes the domain to match any name
below it), "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns. A "/file/name"
pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table
is matched when a table entry matches a lookup string (the lookup
result is ignored). Continue long lines by starting the next line
with whitespace. Specify "!pattern" to exclude an address or network
block from the list. The form "!/file/name" is supported only in
Postfix version 2.4 and later. </p>
<p> Note: IP version 6 address information must be specified inside
<tt>[]</tt> in the <a href="postconf.5.html#smtpd_authorized_xclient_hosts">smtpd_authorized_xclient_hosts</a> value, and in
files specified with "/file/name". IP version 6 addresses contain
the ":" character, and would otherwise be confused with a "<a href="DATABASE_README.html">type:table</a>"
pattern. </p>
</DD>
<DT><b><a name="smtpd_authorized_xforward_hosts">smtpd_authorized_xforward_hosts</a>
(default: empty)</b></DT><DD>
<p>
What remote SMTP clients are allowed to use the XFORWARD feature. This
command forwards information that is used to improve logging after
SMTP-based content filters. See the <a href="XFORWARD_README.html">XFORWARD_README</a> document for
details.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
<p>
By default, no clients are allowed to specify XFORWARD.
</p>
<p>
Specify a list of network/netmask patterns, separated by commas
and/or whitespace. The mask specifies the number of bits in the
network part of a host address. You can also specify hostnames or
.domain names (the initial dot causes the domain to match any name
below it), "/file/name" or "<a href="DATABASE_README.html">type:table</a>" patterns. A "/file/name"
pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table
is matched when a table entry matches a lookup string (the lookup
result is ignored). Continue long lines by starting the next line
with whitespace. Specify "!pattern" to exclude an address or network
block from the list. The form "!/file/name" is supported only in
Postfix version 2.4 and later. </p>
<p> Note: IP version 6 address information must be specified inside
<tt>[]</tt> in the <a href="postconf.5.html#smtpd_authorized_xforward_hosts">smtpd_authorized_xforward_hosts</a> value, and in
files specified with "/file/name". IP version 6 addresses contain
the ":" character, and would otherwise be confused with a "<a href="DATABASE_README.html">type:table</a>"
pattern. </p>
</DD>
<DT><b><a name="smtpd_banner">smtpd_banner</a>
(default: $<a href="postconf.5.html#myhostname">myhostname</a> ESMTP $<a href="postconf.5.html#mail_name">mail_name</a>)</b></DT><DD>
<p>
The text that follows the 220 status code in the SMTP greeting
banner. Some people like to see the mail version advertised. By
default, Postfix shows no version.
</p>
<p>
You MUST specify $<a href="postconf.5.html#myhostname">myhostname</a> at the start of the text. This is
required by the SMTP protocol.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#smtpd_banner">smtpd_banner</a> = $<a href="postconf.5.html#myhostname">myhostname</a> ESMTP $<a href="postconf.5.html#mail_name">mail_name</a> ($<a href="postconf.5.html#mail_version">mail_version</a>)
</pre>
</DD>
<DT><b><a name="smtpd_client_auth_rate_limit">smtpd_client_auth_rate_limit</a>
(default: 0)</b></DT><DD>
<p>
The maximal number of AUTH commands that any client is allowed to
send to this service per time unit, regardless of whether or not
Postfix actually accepts those commands. The time unit is specified
with the <a href="postconf.5.html#anvil_rate_time_unit">anvil_rate_time_unit</a> configuration parameter.
</p>
<p>
By default, there is no limit on the number AUTH commands that a
client may send.
</p>
<p>
To disable this feature, specify a limit of 0.
</p>
<p>
WARNING: The purpose of this feature is to limit abuse. It must
not be used to regulate legitimate mail traffic.
</p>
<p>
This feature is available in Postfix 3.1 and later.
</p>
</DD>
<DT><b><a name="smtpd_client_connection_count_limit">smtpd_client_connection_count_limit</a>
(default: 50)</b></DT><DD>
<p>
How many simultaneous connections any client is allowed to
make to this service. By default, the limit is set to half
the default process limit value.
</p>
<p>
To disable this feature, specify a limit of 0.
</p>
<p>
WARNING: The purpose of this feature is to limit abuse. It must
not be used to regulate legitimate mail traffic.
</p>
<p>
This feature is available in Postfix 2.2 and later.
</p>
</DD>
<DT><b><a name="smtpd_client_connection_rate_limit">smtpd_client_connection_rate_limit</a>
(default: 0)</b></DT><DD>
<p>
The maximal number of connection attempts any client is allowed to
make to this service per time unit. The time unit is specified
with the <a href="postconf.5.html#anvil_rate_time_unit">anvil_rate_time_unit</a> configuration parameter.
</p>
<p>
By default, a client can make as many connections per time unit as
Postfix can accept.
</p>
<p>
To disable this feature, specify a limit of 0.
</p>
<p>
WARNING: The purpose of this feature is to limit abuse. It must
not be used to regulate legitimate mail traffic.
</p>
<p>
This feature is available in Postfix 2.2 and later.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#smtpd_client_connection_rate_limit">smtpd_client_connection_rate_limit</a> = 1000
</pre>
</DD>
<DT><b><a name="smtpd_client_event_limit_exceptions">smtpd_client_event_limit_exceptions</a>
(default: $<a href="postconf.5.html#mynetworks">mynetworks</a>)</b></DT><DD>
<p>
Clients that are excluded from smtpd_client_*_count/rate_limit
restrictions. See the <a href="postconf.5.html#mynetworks">mynetworks</a> parameter
description for the parameter value syntax.
</p>
<p>
By default, clients in trusted networks are excluded. Specify a
list of network blocks, hostnames or .domain names (the initial
dot causes the domain to match any name below it).
</p>
<p> Note: IP version 6 address information must be specified inside
<tt>[]</tt> in the <a href="postconf.5.html#smtpd_client_event_limit_exceptions">smtpd_client_event_limit_exceptions</a> value, and
in files specified with "/file/name". IP version 6 addresses
contain the ":" character, and would otherwise be confused with a
"<a href="DATABASE_README.html">type:table</a>" pattern. </p>
<p> Pattern matching of domain names is controlled by the presence
or absence of "<a href="postconf.5.html#smtpd_client_event_limit_exceptions">smtpd_client_event_limit_exceptions</a>" in the
<a href="postconf.5.html#parent_domain_matches_subdomains">parent_domain_matches_subdomains</a> parameter value (postfix 3.0 and
later). </p>
<p>
This feature is available in Postfix 2.2 and later.
</p>
</DD>
<DT><b><a name="smtpd_client_message_rate_limit">smtpd_client_message_rate_limit</a>
(default: 0)</b></DT><DD>
<p>
The maximal number of message delivery requests that any client is
allowed to make to this service per time unit, regardless of whether
or not Postfix actually accepts those messages. The time unit is
specified with the <a href="postconf.5.html#anvil_rate_time_unit">anvil_rate_time_unit</a> configuration parameter.
</p>
<p>
By default, a client can send as many message delivery requests
per time unit as Postfix can accept.
</p>
<p>
To disable this feature, specify a limit of 0.
</p>
<p>
WARNING: The purpose of this feature is to limit abuse. It must
not be used to regulate legitimate mail traffic.
</p>
<p>
This feature is available in Postfix 2.2 and later.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#smtpd_client_message_rate_limit">smtpd_client_message_rate_limit</a> = 1000
</pre>
</DD>
<DT><b><a name="smtpd_client_new_tls_session_rate_limit">smtpd_client_new_tls_session_rate_limit</a>
(default: 0)</b></DT><DD>
<p>
The maximal number of new (i.e., uncached) TLS sessions that a
remote SMTP client is allowed to negotiate with this service per
time unit. The time unit is specified with the <a href="postconf.5.html#anvil_rate_time_unit">anvil_rate_time_unit</a>
configuration parameter.
</p>
<p>
By default, a remote SMTP client can negotiate as many new TLS
sessions per time unit as Postfix can accept.
</p>
<p>
To disable this feature, specify a limit of 0. Otherwise, specify
a limit that is at least the per-client concurrent session limit,
or else legitimate client sessions may be rejected.
</p>
<p>
WARNING: The purpose of this feature is to limit abuse. It must
not be used to regulate legitimate mail traffic.
</p>
<p>
This feature is available in Postfix 2.3 and later.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#smtpd_client_new_tls_session_rate_limit">smtpd_client_new_tls_session_rate_limit</a> = 100
</pre>
</DD>
<DT><b><a name="smtpd_client_port_logging">smtpd_client_port_logging</a>
(default: no)</b></DT><DD>
<p> Enable logging of the remote SMTP client port in addition to
the hostname and IP address. The logging format is "host[address]:port".
</p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="smtpd_client_recipient_rate_limit">smtpd_client_recipient_rate_limit</a>
(default: 0)</b></DT><DD>
<p>
The maximal number of recipient addresses that any client is allowed
to send to this service per time unit, regardless of whether or not
Postfix actually accepts those recipients. The time unit is specified
with the <a href="postconf.5.html#anvil_rate_time_unit">anvil_rate_time_unit</a> configuration parameter.
</p>
<p>
By default, a client can send as many recipient addresses per time
unit as Postfix can accept.
</p>
<p>
To disable this feature, specify a limit of 0.
</p>
<p>
WARNING: The purpose of this feature is to limit abuse. It must
not be used to regulate legitimate mail traffic.
</p>
<p>
This feature is available in Postfix 2.2 and later.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#smtpd_client_recipient_rate_limit">smtpd_client_recipient_rate_limit</a> = 1000
</pre>
</DD>
<DT><b><a name="smtpd_client_restrictions">smtpd_client_restrictions</a>
(default: empty)</b></DT><DD>
<p>
Optional restrictions that the Postfix SMTP server applies in the
context of a client connection request.
See <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, section "Delayed evaluation of SMTP access
restriction lists" for a discussion of evaluation context and time.
</p>
<p>
The default is to allow all connection requests.
</p>
<p>
Specify a list of restrictions, separated by commas and/or whitespace.
Continue long lines by starting the next line with whitespace.
Restrictions are applied in the order as specified; the first
restriction that matches wins.
</p>
<p>
The following restrictions are specific to client hostname or
client network address information.
</p>
<dl>
<dt><b><a name="check_ccert_access">check_ccert_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd> Use the remote SMTP client certificate fingerprint or the public key
fingerprint (Postfix 2.9 and later) as lookup key for the specified
<a href="access.5.html">access(5)</a> database; with Postfix version 2.2, also require that the
remote SMTP client certificate is verified successfully.
The fingerprint digest algorithm is configurable via the
<a href="postconf.5.html#smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a> parameter (hard-coded as md5 prior to
Postfix version 2.5). This feature is available with Postfix version
2.2 and later. </dd>
<dt><b><a name="check_client_access">check_client_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd>Search the specified access database for the client hostname,
parent domains, client IP address, or networks obtained by stripping
least significant octets. See the <a href="access.5.html">access(5)</a> manual page for details. </dd>
<dt><b><a name="check_client_a_access">check_client_a_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd>Search the specified <a href="access.5.html">access(5)</a> database for the IP addresses for the
client hostname, and execute the corresponding action. Note: a result
of "OK" is not allowed for safety reasons. Instead, use DUNNO in order
to exclude specific hosts from blacklists. This feature is available
in Postfix 3.0 and later. </dd>
<dt><b><a name="check_client_mx_access">check_client_mx_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd>Search the specified <a href="access.5.html">access(5)</a> database for the MX hosts for the
client hostname, and execute the corresponding action. Note: a result
of "OK" is not allowed for safety reasons. Instead, use DUNNO in order
to exclude specific hosts from blacklists. This feature is available
in Postfix 2.7 and later. </dd>
<dt><b><a name="check_client_ns_access">check_client_ns_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd>Search the specified <a href="access.5.html">access(5)</a> database for the DNS servers for
the client hostname, and execute the corresponding action. Note: a
result of "OK" is not allowed for safety reasons. Instead, use DUNNO
in order to exclude specific hosts from blacklists. This feature is
available in Postfix 2.7 and later. </dd>
<dt><b><a name="check_reverse_client_hostname_access">check_reverse_client_hostname_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd>Search the specified access database for the unverified reverse
client hostname, parent domains, client IP address, or networks
obtained by stripping least significant octets. See the <a href="access.5.html">access(5)</a>
manual page for details. Note: a result of "OK" is not allowed for
safety reasons. Instead, use DUNNO in order to exclude specific
hosts from blacklists. This feature is available in Postfix 2.6
and later.</dd>
<dt><b><a name="check_reverse_client_hostname_a_access">check_reverse_client_hostname_a_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd>Search the specified <a href="access.5.html">access(5)</a> database for the IP addresses for the
unverified reverse client hostname, and execute the corresponding
action. Note: a result of "OK" is not allowed for safety reasons.
Instead, use DUNNO in order to exclude specific hosts from blacklists.
This feature is available in Postfix 3.0 and later. </dd>
<dt><b><a name="check_reverse_client_hostname_mx_access">check_reverse_client_hostname_mx_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd>Search the specified <a href="access.5.html">access(5)</a> database for the MX hosts for the
unverified reverse client hostname, and execute the corresponding
action. Note: a result of "OK" is not allowed for safety reasons.
Instead, use DUNNO in order to exclude specific hosts from blacklists.
This feature is available in Postfix 2.7 and later. </dd>
<dt><b><a name="check_reverse_client_hostname_ns_access">check_reverse_client_hostname_ns_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd>Search the specified <a href="access.5.html">access(5)</a> database for the DNS servers for
the unverified reverse client hostname, and execute the corresponding
action. Note: a result of "OK" is not allowed for safety reasons.
Instead, use DUNNO in order to exclude specific hosts from blacklists.
This feature is available in Postfix 2.7 and later. </dd>
<dt><b><a name="check_sasl_access">check_sasl_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd> Use the remote SMTP client SASL user name as lookup key for
the specified <a href="access.5.html">access(5)</a> database. The lookup key has the form
"username@domainname" when the <a href="postconf.5.html#smtpd_sasl_local_domain">smtpd_sasl_local_domain</a> parameter
value is non-empty. Unlike the <a href="postconf.5.html#check_client_access">check_client_access</a> feature,
<a href="postconf.5.html#check_sasl_access">check_sasl_access</a> does not perform matches of parent domains or IP
subnet ranges. This feature is available with Postfix version 2.11
and later. </dd>
<dt><b><a name="permit_inet_interfaces">permit_inet_interfaces</a></b></dt>
<dd>Permit the request when the client IP address matches
$<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>. </dd>
<dt><b><a name="permit_mynetworks">permit_mynetworks</a></b></dt>
<dd>Permit the request when the client IP address matches any
network or network address listed in $<a href="postconf.5.html#mynetworks">mynetworks</a>. </dd>
<dt><b><a name="permit_sasl_authenticated">permit_sasl_authenticated</a></b></dt>
<dd> Permit the request when the client is successfully
authenticated via the <a href="http://tools.ietf.org/html/rfc4954">RFC 4954</a> (AUTH) protocol. </dd>
<dt><b><a name="permit_tls_all_clientcerts">permit_tls_all_clientcerts</a></b></dt>
<dd> Permit the request when the remote SMTP client certificate is
verified successfully. This option must be used only if a special
CA issues the certificates and only this CA is listed as trusted
CA. Otherwise, clients with a third-party certificate would also
be allowed to relay. Specify "<a href="postconf.5.html#tls_append_default_CA">tls_append_default_CA</a> = no" when the
trusted CA is specified with <a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a> or <a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a>,
to prevent Postfix from appending the system-supplied default CAs.
This feature is available with Postfix version 2.2.</dd>
<dt><b><a name="permit_tls_clientcerts">permit_tls_clientcerts</a></b></dt>
<dd>Permit the request when the remote SMTP client certificate
fingerprint or public key fingerprint (Postfix 2.9 and later) is
listed in $<a href="postconf.5.html#relay_clientcerts">relay_clientcerts</a>.
The fingerprint digest algorithm is configurable via the
<a href="postconf.5.html#smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a> parameter (hard-coded as md5 prior to
Postfix version 2.5). This feature is available with Postfix version
2.2. </dd>
<dt><b><a name="reject_rbl_client">reject_rbl_client <i>rbl_domain=d.d.d.d</i></a></b></dt>
<dd>Reject the request when the reversed client network address is
listed with the A record "<i>d.d.d.d</i>" under <i>rbl_domain</i>
(Postfix version 2.1 and later only). Each "<i>d</i>" is a number,
or a pattern inside "[]" that contains one or more ";"-separated
numbers or number..number ranges (Postfix version 2.8 and later).
If no "<i>=d.d.d.d</i>" is specified, reject the request when the
reversed client network address is listed with any A record under
<i>rbl_domain</i>. <br>
The <a href="postconf.5.html#maps_rbl_reject_code">maps_rbl_reject_code</a> parameter specifies the response code for
rejected requests (default: 554), the <a href="postconf.5.html#default_rbl_reply">default_rbl_reply</a> parameter
specifies the default server reply, and the <a href="postconf.5.html#rbl_reply_maps">rbl_reply_maps</a> parameter
specifies tables with server replies indexed by <i>rbl_domain</i>.
This feature is available in Postfix 2.0 and later. </dd>
<dt><b><a name="permit_dnswl_client">permit_dnswl_client <i>dnswl_domain=d.d.d.d</i></a></b></dt>
<dd>Accept the request when the reversed client network address is
listed with the A record "<i>d.d.d.d</i>" under <i>dnswl_domain</i>.
Each "<i>d</i>" is a number, or a pattern inside "[]" that contains
one or more ";"-separated numbers or number..number ranges.
If no "<i>=d.d.d.d</i>" is specified, accept the request when the
reversed client network address is listed with any A record under
<i>dnswl_domain</i>. <br> For safety, <a href="postconf.5.html#permit_dnswl_client">permit_dnswl_client</a> is silently
ignored when it would override <a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a>. The
result is DEFER_IF_REJECT when whitelist lookup fails. This feature
is available in Postfix 2.8 and later. </dd>
<dt><b><a name="reject_rhsbl_client">reject_rhsbl_client <i>rbl_domain=d.d.d.d</i></a></b></dt>
<dd>Reject the request when the client hostname is listed with the
A record "<i>d.d.d.d</i>" under <i>rbl_domain</i> (Postfix version
2.1 and later only). Each "<i>d</i>" is a number, or a pattern
inside "[]" that contains one or more ";"-separated numbers or
number..number ranges (Postfix version 2.8 and later). If no
"<i>=d.d.d.d</i>" is specified, reject the request when the client
hostname is listed with
any A record under <i>rbl_domain</i>. See the <a href="postconf.5.html#reject_rbl_client">reject_rbl_client</a>
description above for additional RBL related configuration parameters.
This feature is available in Postfix 2.0 and later; with Postfix
version 2.8 and later, <a href="postconf.5.html#reject_rhsbl_reverse_client">reject_rhsbl_reverse_client</a> will usually
produce better results. </dd>
<dt><b><a name="permit_rhswl_client">permit_rhswl_client <i>rhswl_domain=d.d.d.d</i></a></b></dt>
<dd>Accept the request when the client hostname is listed with the
A record "<i>d.d.d.d</i>" under <i>rhswl_domain</i>. Each "<i>d</i>"
is a number, or a pattern inside "[]" that contains one or more
";"-separated numbers or number..number ranges. If no
"<i>=d.d.d.d</i>" is specified, accept the request when the client
hostname is listed with any A record under <i>rhswl_domain</i>.
<br> Caution: client name whitelisting is fragile, since the client
name lookup can fail due to temporary outages. Client name
whitelisting should be used only to reduce false positives in e.g.
DNS-based blocklists, and not for making access rule exceptions.
<br> For safety, <a href="postconf.5.html#permit_rhswl_client">permit_rhswl_client</a> is silently ignored when it
would override <a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a>. The result is DEFER_IF_REJECT
when whitelist lookup fails. This feature is available in Postfix
2.8 and later. </dd>
<dt><b><a name="reject_rhsbl_reverse_client">reject_rhsbl_reverse_client <i>rbl_domain=d.d.d.d</i></a></b></dt>
<dd>Reject the request when the unverified reverse client hostname
is listed with the A record "<i>d.d.d.d</i>" under <i>rbl_domain</i>.
Each "<i>d</i>" is a number, or a pattern inside "[]" that contains
one or more ";"-separated numbers or number..number ranges.
If no "<i>=d.d.d.d</i>" is specified, reject the request when the
unverified reverse client hostname is listed with any A record under
<i>rbl_domain</i>. See the <a href="postconf.5.html#reject_rbl_client">reject_rbl_client</a> description above for
additional RBL related configuration parameters. This feature is
available in Postfix 2.8 and later. </dd>
<dt><b><a name="reject_unknown_client_hostname">reject_unknown_client_hostname</a></b> (with Postfix < 2.3: reject_unknown_client)</dt>
<dd>Reject the request when 1) the client IP address->name mapping
fails, 2) the name->address mapping fails, or 3) the name->address
mapping does not match the client IP address. <br> This is a
stronger restriction than the <a href="postconf.5.html#reject_unknown_reverse_client_hostname">reject_unknown_reverse_client_hostname</a>
feature, which triggers only under condition 1) above. <br> The
<a href="postconf.5.html#unknown_client_reject_code">unknown_client_reject_code</a> parameter specifies the response code
for rejected requests (default: 450). The reply is always 450 in
case the address->name or name->address lookup failed due to
a temporary problem. </dd>
<dt><b><a name="reject_unknown_reverse_client_hostname">reject_unknown_reverse_client_hostname</a></b></dt>
<dd>Reject the request when the client IP address has no address->name
mapping. <br> This is a weaker restriction than the
<a href="postconf.5.html#reject_unknown_client_hostname">reject_unknown_client_hostname</a> feature, which requires not only
that the address->name and name->address mappings exist, but
also that the two mappings reproduce the client IP address. <br>
The <a href="postconf.5.html#unknown_client_reject_code">unknown_client_reject_code</a> parameter specifies the response
code for rejected requests (default: 450). The reply is always 450
in case the address->name lookup failed due to a temporary
problem. <br> This feature is available in Postfix 2.3 and
later. </dd>
</dl>
<p>
In addition, you can use any of the following <a name="generic">
generic</a> restrictions. These restrictions are applicable in
any SMTP command context.
</p>
<dl>
<dt><b><a name="check_policy_service">check_policy_service <i>servername</i></a></b></dt>
<dd>Query the specified policy server. See the <a href="SMTPD_POLICY_README.html">SMTPD_POLICY_README</a>
document for details. This feature is available in Postfix 2.1
and later. </dd>
<dt><b><a name="defer">defer</a></b></dt>
<dd>Defer the request. The client is told to try again later. This
restriction is useful at the end of a restriction list, to make
the default policy explicit. <br> The <a href="postconf.5.html#defer_code">defer_code</a> parameter specifies
the SMTP server reply code (default: 450).</dd>
<dt><b><a name="defer_if_permit">defer_if_permit</a></b></dt>
<dd>Defer the request if some later restriction would result in an
explicit or implicit PERMIT action. This is useful when a blacklisting
feature fails due to a temporary problem. This feature is available
in Postfix version 2.1 and later. </dd>
<dt><b><a name="defer_if_reject">defer_if_reject</a></b></dt>
<dd>Defer the request if some later restriction would result in a
REJECT action. This is useful when a whitelisting feature fails
due to a temporary problem. This feature is available in Postfix
version 2.1 and later. </dd>
<dt><b><a name="permit">permit</a></b></dt>
<dd>Permit the request. This restriction is useful at the end of
a restriction list, to make the default policy explicit.</dd>
<dt><b><a name="reject_multi_recipient_bounce">reject_multi_recipient_bounce</a></b></dt>
<dd>Reject the request when the envelope sender is the null address,
and the message has multiple envelope recipients. This usage has
rare but legitimate applications: under certain conditions,
multi-recipient mail that was posted with the DSN option NOTIFY=NEVER
may be forwarded with the null sender address.
<br> Note: this restriction can only work reliably
when used in <a href="postconf.5.html#smtpd_data_restrictions">smtpd_data_restrictions</a> or
<a href="postconf.5.html#smtpd_end_of_data_restrictions">smtpd_end_of_data_restrictions</a>, because the total number of
recipients is not known at an earlier stage of the SMTP conversation.
Use at the RCPT stage will only reject the second etc. recipient.
<br>
The <a href="postconf.5.html#multi_recipient_bounce_reject_code">multi_recipient_bounce_reject_code</a> parameter specifies the
response code for rejected requests (default: 550). This feature
is available in Postfix 2.1 and later. </dd>
<dt><b><a name="reject_plaintext_session">reject_plaintext_session</a></b></dt>
<dd>Reject the request when the connection is not encrypted. This
restriction should not be used before the client has had a chance
to negotiate encryption with the AUTH or STARTTLS commands.
<br>
The <a href="postconf.5.html#plaintext_reject_code">plaintext_reject_code</a> parameter specifies the response
code for rejected requests (default: 450). This feature is available
in Postfix 2.3 and later. </dd>
<dt><b><a name="reject_unauth_pipelining">reject_unauth_pipelining</a></b></dt>
<dd>Reject the request when the client sends SMTP commands ahead
of time where it is not allowed, or when the client sends SMTP
commands ahead of time without knowing that Postfix actually supports
ESMTP command pipelining. This stops mail from bulk mail software
that improperly uses ESMTP command pipelining in order to speed up
deliveries.
<br> With Postfix 2.6 and later, the SMTP server sets a per-session
flag whenever it detects illegal pipelining, including pipelined
HELO or EHLO commands. The <a href="postconf.5.html#reject_unauth_pipelining">reject_unauth_pipelining</a> feature simply
tests whether the flag was set at any point in time during the
session.
<br> With older Postfix versions, <a href="postconf.5.html#reject_unauth_pipelining">reject_unauth_pipelining</a> checks
the current status of the input read queue, and its usage is not
recommended in contexts other than <a href="postconf.5.html#smtpd_data_restrictions">smtpd_data_restrictions</a>. </dd>
<dt><b><a name="reject">reject</a></b></dt>
<dd>Reject the request. This restriction is useful at the end of
a restriction list, to make the default policy explicit. The
<a href="postconf.5.html#reject_code">reject_code</a> configuration parameter specifies the response code for
rejected requests (default: 554).</dd>
<dt><b><a name="sleep">sleep <i>seconds</i></a></b></dt>
<dd>Pause for the specified number of seconds and proceed with
the next restriction in the list, if any. This may stop zombie
mail when used as:
<pre>
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
<a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> =
sleep 1, <a href="postconf.5.html#reject_unauth_pipelining">reject_unauth_pipelining</a>
<a href="postconf.5.html#smtpd_delay_reject">smtpd_delay_reject</a> = no
</pre>
This feature is available in Postfix 2.3. </dd>
<dt><b><a name="warn_if_reject">warn_if_reject</a></b></dt>
<dd> A safety net for testing. When "<a href="postconf.5.html#warn_if_reject">warn_if_reject</a>" is placed
before a reject-type restriction, access table query, or
<a href="postconf.5.html#check_policy_service">check_policy_service</a> query, this logs a "reject_warning" message
instead of rejecting a request (when a reject-type restriction fails
due to a temporary error, this logs a "reject_warning" message for
any implicit "<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>" actions that would normally prevent
mail from being accepted by some later access restriction). This
feature has no effect on <a href="postconf.5.html#defer_if_reject">defer_if_reject</a> restrictions. </dd>
</dl>
<p>
Other restrictions that are valid in this context:
</p>
<ul>
<li> SMTP command specific restrictions that are described under
the <a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a>, <a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a> or
<a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> parameters. When helo, sender or
recipient restrictions are listed under <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>,
they have effect only with "<a href="postconf.5.html#smtpd_delay_reject">smtpd_delay_reject</a> = yes", so that
$<a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> is evaluated at the time of the RCPT TO
command.
</ul>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> = <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>, <a href="postconf.5.html#reject_unknown_client_hostname">reject_unknown_client_hostname</a>
</pre>
</DD>
<DT><b><a name="smtpd_command_filter">smtpd_command_filter</a>
(default: empty)</b></DT><DD>
<p> A mechanism to transform commands from remote SMTP clients.
This is a last-resort tool to work around client commands that break
interoperability with the Postfix SMTP server. Other uses involve
fault injection to test Postfix's handling of invalid commands.
</p>
<p> Specify the name of a "<a href="DATABASE_README.html">type:table</a>" lookup table. The search
string is the SMTP command as received from the remote SMTP client,
except that initial whitespace and the trailing <CR><LF>
are removed. The result value is executed by the Postfix SMTP
server. </p>
<p> There is no need to use <a href="postconf.5.html#smtpd_command_filter">smtpd_command_filter</a> for the following
cases: </p>
<ul>
<li> <p> Use "<a href="postconf.5.html#resolve_numeric_domain">resolve_numeric_domain</a> = yes" to accept
"<i>user@ipaddress</i>". </p>
<li> <p> Postfix already accepts the correct form
"<i>user@[ipaddress]</i>". Use <a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a> or <a href="postconf.5.html#canonical_maps">canonical_maps</a>
to translate these into domain names if necessary. </p>
<li> <p> Use "<a href="postconf.5.html#strict_rfc821_envelopes">strict_rfc821_envelopes</a> = no" to accept "RCPT TO:<<i>User
Name <user@example.com>></i>". Postfix will ignore the "<i>User
Name</i>" part and deliver to the <i><user@example.com></i> address.
</p>
</ul>
<p> Examples of problems that can be solved with the <a href="postconf.5.html#smtpd_command_filter">smtpd_command_filter</a>
feature: </p>
<pre>
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
<a href="postconf.5.html#smtpd_command_filter">smtpd_command_filter</a> = <a href="pcre_table.5.html">pcre</a>:/etc/postfix/command_filter
</pre>
<pre>
/etc/postfix/command_filter:
# Work around clients that send malformed HELO commands.
/^HELO\s*$/ HELO domain.invalid
</pre>
<pre>
# Work around clients that send empty lines.
/^\s*$/ NOOP
</pre>
<pre>
# Work around clients that send RCPT TO:<'user@domain'>.
# WARNING: do not lose the parameters that follow the address.
/^(RCPT\s+TO:\s*<)'([^[:space:]]+)'(>.*)/ $1$2$3
</pre>
<pre>
# Append XVERP to MAIL FROM commands to request VERP-style delivery.
# See <a href="VERP_README.html">VERP_README</a> for more information on how to use Postfix VERP.
/^(MAIL FROM:\s*<listname@example\.com>.*)/ $1 XVERP
</pre>
<pre>
# Bounce-never mail sink. Use <a href="postconf.5.html#notify_classes">notify_classes</a>=bounce,resource,software
# to send bounced mail to the postmaster (with message body removed).
/^(RCPT\s+TO:\s*<.*>.*)\s+NOTIFY=\S+(.*)/ $1 NOTIFY=NEVER$2
/^(RCPT\s+TO:.*)/ $1 NOTIFY=NEVER
</pre>
<p> This feature is available in Postfix 2.7. </p>
</DD>
<DT><b><a name="smtpd_data_restrictions">smtpd_data_restrictions</a>
(default: empty)</b></DT><DD>
<p>
Optional access restrictions that the Postfix SMTP server applies
in the context of the SMTP DATA command.
See <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, section "Delayed evaluation of SMTP access
restriction lists" for a discussion of evaluation context and time.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
<p>
Specify a list of restrictions, separated by commas and/or whitespace.
Continue long lines by starting the next line with whitespace.
Restrictions are applied in the order as specified; the first
restriction that matches wins.
</p>
<p>
The following restrictions are valid in this context:
</p>
<ul>
<li><a href="#generic">Generic</a> restrictions that can be used
in any SMTP command context, described under <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>.
<li>SMTP command specific restrictions described under
<a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>, <a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a>,
<a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a> or <a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a>.
<li>However, no recipient information is available in the case of
multi-recipient mail. Acting on only one recipient would be misleading,
because any decision will affect all recipients equally. Acting on
all recipients would require a possibly very large amount of memory,
and would also be misleading for the reasons mentioned before.
</ul>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#smtpd_data_restrictions">smtpd_data_restrictions</a> = <a href="postconf.5.html#reject_unauth_pipelining">reject_unauth_pipelining</a>
<a href="postconf.5.html#smtpd_data_restrictions">smtpd_data_restrictions</a> = <a href="postconf.5.html#reject_multi_recipient_bounce">reject_multi_recipient_bounce</a>
</pre>
</DD>
<DT><b><a name="smtpd_delay_open_until_valid_rcpt">smtpd_delay_open_until_valid_rcpt</a>
(default: yes)</b></DT><DD>
<p> Postpone the start of an SMTP mail transaction until a valid
RCPT TO command is received. Specify "no" to create a mail transaction
as soon as the Postfix SMTP server receives a valid MAIL FROM
command. </p>
<p> With sites that reject lots of mail, the default setting reduces
the use of
disk, CPU and memory resources. The downside is that rejected
recipients are logged with NOQUEUE instead of a mail transaction
ID. This complicates the logfile analysis of multi-recipient mail.
</p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="smtpd_delay_reject">smtpd_delay_reject</a>
(default: yes)</b></DT><DD>
<p>
Wait until the RCPT TO command before evaluating
$<a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>, $<a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a> and
$<a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a>, or wait until the ETRN command before
evaluating $<a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> and $<a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a>.
</p>
<p>
This feature is turned on by default because some clients apparently
mis-behave when the Postfix SMTP server rejects commands before
RCPT TO.
</p>
<p>
The default setting has one major benefit: it allows Postfix to log
recipient address information when rejecting a client name/address
or sender address, so that it is possible to find out whose mail
is being rejected.
</p>
</DD>
<DT><b><a name="smtpd_discard_ehlo_keyword_address_maps">smtpd_discard_ehlo_keyword_address_maps</a>
(default: empty)</b></DT><DD>
<p> Lookup tables, indexed by the remote SMTP client address, with
case insensitive lists of EHLO keywords (pipelining, starttls, auth,
etc.) that the Postfix SMTP server will not send in the EHLO response
to a
remote SMTP client. See <a href="postconf.5.html#smtpd_discard_ehlo_keywords">smtpd_discard_ehlo_keywords</a> for details.
The tables are not searched by hostname for robustness reasons. </p>
<p>
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found.
</p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtpd_discard_ehlo_keywords">smtpd_discard_ehlo_keywords</a>
(default: empty)</b></DT><DD>
<p> A case insensitive list of EHLO keywords (pipelining, starttls,
auth, etc.) that the Postfix SMTP server will not send in the EHLO
response
to a remote SMTP client. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
<p> Notes: </p>
<ul>
<li> <p> Specify the <b>silent-discard</b> pseudo keyword to prevent
this action from being logged. </p>
<li> <p> Use the <a href="postconf.5.html#smtpd_discard_ehlo_keyword_address_maps">smtpd_discard_ehlo_keyword_address_maps</a> feature
to discard EHLO keywords selectively. </p>
</ul>
</DD>
<DT><b><a name="smtpd_dns_reply_filter">smtpd_dns_reply_filter</a>
(default: empty)</b></DT><DD>
<p> Optional filter for Postfix SMTP server DNS lookup results.
See <a href="postconf.5.html#smtp_dns_reply_filter">smtp_dns_reply_filter</a> for details including an example.
</p>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="smtpd_end_of_data_restrictions">smtpd_end_of_data_restrictions</a>
(default: empty)</b></DT><DD>
<p> Optional access restrictions that the Postfix SMTP server
applies in the context of the SMTP END-OF-DATA command.
See <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, section "Delayed evaluation of SMTP access
restriction lists" for a discussion of evaluation context and time.
</p>
<p> This feature is available in Postfix 2.2 and later. </p>
<p> See <a href="postconf.5.html#smtpd_data_restrictions">smtpd_data_restrictions</a> for details and limitations. </p>
</DD>
<DT><b><a name="smtpd_enforce_tls">smtpd_enforce_tls</a>
(default: no)</b></DT><DD>
<p> Mandatory TLS: announce STARTTLS support to remote SMTP clients,
and require that clients use TLS encryption. According to <a href="http://tools.ietf.org/html/rfc2487">RFC 2487</a>
this MUST NOT be applied in case of a publicly-referenced SMTP
server. This option is therefore off by default. </p>
<p> Note 1: "<a href="postconf.5.html#smtpd_enforce_tls">smtpd_enforce_tls</a> = yes" implies "<a href="postconf.5.html#smtpd_tls_auth_only">smtpd_tls_auth_only</a> = yes". </p>
<p> Note 2: when invoked via "<b>sendmail -bs</b>", Postfix will never offer
STARTTLS due to insufficient privileges to access the server private
key. This is intended behavior. </p>
<p> This feature is available in Postfix 2.2 and later. With
Postfix 2.3 and later use <a href="postconf.5.html#smtpd_tls_security_level">smtpd_tls_security_level</a> instead. </p>
</DD>
<DT><b><a name="smtpd_error_sleep_time">smtpd_error_sleep_time</a>
(default: 1s)</b></DT><DD>
<p>With Postfix version 2.1 and later: the SMTP server response delay after
a client has made more than $<a href="postconf.5.html#smtpd_soft_error_limit">smtpd_soft_error_limit</a> errors, and
fewer than $<a href="postconf.5.html#smtpd_hard_error_limit">smtpd_hard_error_limit</a> errors, without delivering mail.
</p>
<p>With Postfix version 2.0 and earlier: the SMTP server delay before
sending a reject (4xx or 5xx) response, when the client has made
fewer than $<a href="postconf.5.html#smtpd_soft_error_limit">smtpd_soft_error_limit</a> errors without delivering
mail. </p>
</DD>
<DT><b><a name="smtpd_etrn_restrictions">smtpd_etrn_restrictions</a>
(default: empty)</b></DT><DD>
<p>
Optional restrictions that the Postfix SMTP server applies in the
context of a client ETRN command.
See <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, section "Delayed evaluation of SMTP access
restriction lists" for a discussion of evaluation context and time.
</p>
<p>
The Postfix ETRN implementation accepts only destinations that are
eligible for the Postfix "fast flush" service. See the <a href="ETRN_README.html">ETRN_README</a>
file for details.
</p>
<p>
Specify a list of restrictions, separated by commas and/or whitespace.
Continue long lines by starting the next line with whitespace.
Restrictions are applied in the order as specified; the first
restriction that matches wins.
</p>
<p>
The following restrictions are specific to the domain name information
received with the ETRN command.
</p>
<dl>
<dt><b><a name="check_etrn_access">check_etrn_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd>Search the specified access database for the ETRN domain name
or its parent domains. See the <a href="access.5.html">access(5)</a> manual page for details.
</dd>
</dl>
<p>
Other restrictions that are valid in this context:
</p>
<ul>
<li><a href="#generic">Generic</a> restrictions that can be used
in any SMTP command context, described under <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>.
<li>SMTP command specific restrictions described under
<a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> and <a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a>.
</ul>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#smtpd_etrn_restrictions">smtpd_etrn_restrictions</a> = <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>, reject
</pre>
</DD>
<DT><b><a name="smtpd_expansion_filter">smtpd_expansion_filter</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
What characters are allowed in $name expansions of RBL reply
templates. Characters not in the allowed set are replaced by "_".
Use C like escapes to specify special characters such as whitespace.
</p>
<p>
This parameter is not subjected to $parameter expansion.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="smtpd_forbidden_commands">smtpd_forbidden_commands</a>
(default: CONNECT, GET, POST)</b></DT><DD>
<p>
List of commands that cause the Postfix SMTP server to immediately
terminate the session with a 221 code. This can be used to disconnect
clients that obviously attempt to abuse the system. In addition to the
commands listed in this parameter, commands that follow the "Label:"
format of message headers will also cause a disconnect.
</p>
<p>
This feature is available in Postfix 2.2 and later.
</p>
</DD>
<DT><b><a name="smtpd_hard_error_limit">smtpd_hard_error_limit</a>
(default: normal: 20, overload: 1)</b></DT><DD>
<p>
The maximal number of errors a remote SMTP client is allowed to
make without delivering mail. The Postfix SMTP server disconnects
when the limit is exceeded. Normally the default limit is 20, but
it changes under overload to just 1. With Postfix 2.5 and earlier,
the SMTP server always allows up to 20 errors by default.
</p>
</DD>
<DT><b><a name="smtpd_helo_required">smtpd_helo_required</a>
(default: no)</b></DT><DD>
<p>
Require that a remote SMTP client introduces itself with the HELO
or EHLO command before sending the MAIL command or other commands
that require EHLO negotiation.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes
</pre>
</DD>
<DT><b><a name="smtpd_helo_restrictions">smtpd_helo_restrictions</a>
(default: empty)</b></DT><DD>
<p>
Optional restrictions that the Postfix SMTP server applies in the
context of a client HELO command.
See <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, section "Delayed evaluation of SMTP access
restriction lists" for a discussion of evaluation context and time.
</p>
<p>
The default is to permit everything.
</p>
<p> Note: specify "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes" to fully enforce this
restriction (without "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes", a client can
simply skip <a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a> by not sending HELO or EHLO).
</p>
<p>
Specify a list of restrictions, separated by commas and/or whitespace.
Continue long lines by starting the next line with whitespace.
Restrictions are applied in the order as specified; the first
restriction that matches wins.
</p>
<p>
The following restrictions are specific to the hostname information
received with the HELO or EHLO command.
</p>
<dl>
<dt><b><a name="check_helo_access">check_helo_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd>Search the specified <a href="access.5.html">access(5)</a> database for the HELO or EHLO
hostname or parent domains, and execute the corresponding action.
Note: specify "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes" to fully enforce this
restriction (without "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes", a client can
simply skip <a href="postconf.5.html#check_helo_access">check_helo_access</a> by not sending HELO or EHLO). </dd>
<dt><b><a name="check_helo_a_access">check_helo_a_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd>Search the specified <a href="access.5.html">access(5)</a> database for the IP addresses for
the HELO or EHLO hostname, and execute the corresponding action.
Note 1: a result of "OK" is not allowed for safety reasons. Instead,
use DUNNO in order to exclude specific hosts from blacklists. Note
2: specify "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes" to fully enforce this
restriction (without "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes", a client can
simply skip check_helo_a_access by not sending HELO or EHLO). This
feature is available in Postfix 3.0 and later.
</dd>
<dt><b><a name="check_helo_mx_access">check_helo_mx_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd>Search the specified <a href="access.5.html">access(5)</a> database for the MX hosts for
the HELO or EHLO hostname, and execute the corresponding action.
Note 1: a result of "OK" is not allowed for safety reasons. Instead,
use DUNNO in order to exclude specific hosts from blacklists. Note
2: specify "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes" to fully enforce this
restriction (without "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes", a client can
simply skip <a href="postconf.5.html#check_helo_mx_access">check_helo_mx_access</a> by not sending HELO or EHLO). This
feature is available in Postfix 2.1 and later.
</dd>
<dt><b><a name="check_helo_ns_access">check_helo_ns_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd>Search the specified <a href="access.5.html">access(5)</a> database for the DNS servers
for the HELO or EHLO hostname, and execute the corresponding action.
Note 1: a result of "OK" is not allowed for safety reasons. Instead,
use DUNNO in order to exclude specific hosts from blacklists. Note
2: specify "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes" to fully enforce this
restriction (without "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes", a client can
simply skip <a href="postconf.5.html#check_helo_ns_access">check_helo_ns_access</a> by not sending HELO or EHLO). This
feature is available in Postfix 2.1 and later.
</dd>
<dt><b><a name="reject_invalid_helo_hostname">reject_invalid_helo_hostname</a></b> (with Postfix < 2.3: reject_invalid_hostname)</dt>
<dd>Reject the request when the HELO or EHLO hostname is malformed.
Note: specify "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes" to fully enforce
this restriction (without "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes", a client can simply
skip <a href="postconf.5.html#reject_invalid_helo_hostname">reject_invalid_helo_hostname</a> by not sending HELO or EHLO).
<br> The <a href="postconf.5.html#invalid_hostname_reject_code">invalid_hostname_reject_code</a> specifies the response code
for rejected requests (default: 501).</dd>
<dt><b><a name="reject_non_fqdn_helo_hostname">reject_non_fqdn_helo_hostname</a></b> (with Postfix < 2.3: reject_non_fqdn_hostname)</dt>
<dd>Reject the request when the HELO or EHLO hostname is not in
fully-qualified domain or address literal form, as required by the
RFC. Note: specify
"<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes" to fully enforce this restriction
(without "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes", a client can simply skip
<a href="postconf.5.html#reject_non_fqdn_helo_hostname">reject_non_fqdn_helo_hostname</a> by not sending HELO or EHLO). <br>
The <a href="postconf.5.html#non_fqdn_reject_code">non_fqdn_reject_code</a> parameter specifies the response code for
rejected requests (default: 504).</dd>
<dt><b><a name="reject_rhsbl_helo">reject_rhsbl_helo <i>rbl_domain=d.d.d.d</i></a></b></dt>
<dd>Reject the request when the HELO or EHLO hostname is
listed with the A record "<i>d.d.d.d</i>" under <i>rbl_domain</i>
(Postfix version 2.1 and later only). Each "<i>d</i>" is a number,
or a pattern inside "[]" that contains one or more ";"-separated
numbers or number..number ranges (Postfix version 2.8 and later).
If no "<i>=d.d.d.d</i>" is
specified, reject the request when the HELO or EHLO hostname is
listed with any A record under <i>rbl_domain</i>. See the
<a href="postconf.5.html#reject_rbl_client">reject_rbl_client</a> description for additional RBL related configuration
parameters. Note: specify "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes" to fully
enforce this restriction (without "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes", a
client can simply skip <a href="postconf.5.html#reject_rhsbl_helo">reject_rhsbl_helo</a> by not sending HELO or
EHLO). This feature is available in Postfix 2.0
and later. </dd>
<dt><b><a name="reject_unknown_helo_hostname">reject_unknown_helo_hostname</a></b> (with Postfix < 2.3: reject_unknown_hostname)</dt>
<dd>Reject the request when the HELO or EHLO hostname has no DNS A
or MX record. <br> The reply is specified with the
<a href="postconf.5.html#unknown_hostname_reject_code">unknown_hostname_reject_code</a> parameter (default: 450) or
<a href="postconf.5.html#unknown_helo_hostname_tempfail_action">unknown_helo_hostname_tempfail_action</a> (default: <a href="postconf.5.html#defer_if_permit">defer_if_permit</a>).
See the respective parameter descriptions for details. <br>
Note: specify "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes" to fully
enforce this restriction (without "<a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> = yes", a
client can simply skip <a href="postconf.5.html#reject_unknown_helo_hostname">reject_unknown_helo_hostname</a> by not sending
HELO or EHLO). </dd>
</dl>
<p>
Other restrictions that are valid in this context:
</p>
<ul>
<li> <a href="#generic">Generic</a> restrictions that can be used
in any SMTP command context, described under <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>.
<li> Client hostname or network address specific restrictions
described under <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>.
<li> SMTP command specific restrictions described under
<a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a> or <a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a>. When
sender or recipient restrictions are listed under <a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a>,
they have effect only with "<a href="postconf.5.html#smtpd_delay_reject">smtpd_delay_reject</a> = yes", so that
$<a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a> is evaluated at the time of the RCPT TO
command.
</ul>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a> = <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>, <a href="postconf.5.html#reject_invalid_helo_hostname">reject_invalid_helo_hostname</a>
<a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a> = <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>, <a href="postconf.5.html#reject_unknown_helo_hostname">reject_unknown_helo_hostname</a>
</pre>
</DD>
<DT><b><a name="smtpd_history_flush_threshold">smtpd_history_flush_threshold</a>
(default: 100)</b></DT><DD>
<p>
The maximal number of lines in the Postfix SMTP server command history
before it is flushed upon receipt of EHLO, RSET, or end of DATA.
</p>
</DD>
<DT><b><a name="smtpd_junk_command_limit">smtpd_junk_command_limit</a>
(default: normal: 100, overload: 1)</b></DT><DD>
<p>
The number of junk commands (NOOP, VRFY, ETRN or RSET) that a remote
SMTP client can send before the Postfix SMTP server starts to
increment the error counter with each junk command. The junk
command count is reset after mail is delivered. See also the
<a href="postconf.5.html#smtpd_error_sleep_time">smtpd_error_sleep_time</a> and <a href="postconf.5.html#smtpd_soft_error_limit">smtpd_soft_error_limit</a> configuration
parameters. Normally the default limit is 100, but it changes under
overload to just 1. With Postfix 2.5 and earlier, the SMTP server
always allows up to 100 junk commands by default. </p>
</DD>
<DT><b><a name="smtpd_log_access_permit_actions">smtpd_log_access_permit_actions</a>
(default: empty)</b></DT><DD>
<p> Enable logging of the named "permit" actions in SMTP server
access lists (by default, the SMTP server logs "reject" actions but
not "permit" actions). This feature does not affect conditional
actions such as "<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>". </p>
<p> Specify a list of "permit" action names, "/file/name" or
"<a href="DATABASE_README.html">type:table</a>" patterns, separated by commas and/or whitespace. The
list is matched left to right, and the search stops on the first
match. A "/file/name" pattern is replaced by its contents; a
"<a href="DATABASE_README.html">type:table</a>" lookup table is matched when a name matches a lookup
key (the lookup result is ignored). Continue long lines by starting
the next line with whitespace. Specify "!pattern" to exclude a name
from the list. </p>
<p> Examples: </p>
<pre>
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
# Log all "permit" actions.
<a href="postconf.5.html#smtpd_log_access_permit_actions">smtpd_log_access_permit_actions</a> = <a href="DATABASE_README.html#types">static</a>:all
</pre>
<pre>
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
# Log "<a href="postconf.5.html#permit_dnswl_client">permit_dnswl_client</a>" only.
<a href="postconf.5.html#smtpd_log_access_permit_actions">smtpd_log_access_permit_actions</a> = <a href="postconf.5.html#permit_dnswl_client">permit_dnswl_client</a>
</pre>
<p> This feature is available in Postfix 2.10 and later. </p>
</DD>
<DT><b><a name="smtpd_milter_maps">smtpd_milter_maps</a>
(default: empty)</b></DT><DD>
<p> Lookup tables with Milter settings per remote SMTP client IP
address. The lookup result overrides the <a href="postconf.5.html#smtpd_milters">smtpd_milters</a> setting,
and has the same syntax. </p>
<p> Note: lookup tables cannot return empty responses. Specify a
lookup result of DISABLE (case does not matter) to indicate that
Milter support should be disabled. </p>
<p> Example to disable Milters for local clients: </p>
<pre>
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
<a href="postconf.5.html#smtpd_milter_maps">smtpd_milter_maps</a> = <a href="cidr_table.5.html">cidr</a>:/etc/postfix/smtpd_milter_map
<a href="postconf.5.html#smtpd_milters">smtpd_milters</a> = inet:host:port, { inet:host:port, ... }, ...
</pre>
<pre>
/etc/postfix/smtpd_milter_map:
# Disable Milters for local clients.
127.0.0.0/8 DISABLE
192.168.0.0/16 DISABLE
::/64 DISABLE
2001:db8::/32 DISABLE
</pre>
<p> This feature is available in Postfix 3.2 and later. </p>
</DD>
<DT><b><a name="smtpd_milters">smtpd_milters</a>
(default: empty)</b></DT><DD>
<p> A list of Milter (mail filter) applications for new mail that
arrives via the Postfix <a href="smtpd.8.html">smtpd(8)</a> server. Specify space or comma as
separator. See the <a href="MILTER_README.html">MILTER_README</a> document for details. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="smtpd_noop_commands">smtpd_noop_commands</a>
(default: empty)</b></DT><DD>
<p>
List of commands that the Postfix SMTP server replies to with "250
Ok", without doing any syntax checks and without changing state.
This list overrides any commands built into the Postfix SMTP server.
</p>
</DD>
<DT><b><a name="smtpd_null_access_lookup_key">smtpd_null_access_lookup_key</a>
(default: <>)</b></DT><DD>
<p>
The lookup key to be used in SMTP <a href="access.5.html">access(5)</a> tables instead of the
null sender address.
</p>
</DD>
<DT><b><a name="smtpd_peername_lookup">smtpd_peername_lookup</a>
(default: yes)</b></DT><DD>
<p> Attempt to look up the remote SMTP client hostname, and verify that
the name matches the client IP address. A client name is set to
"unknown" when it cannot be looked up or verified, or when name
lookup is disabled. Turning off name lookup reduces delays due to
DNS lookup and increases the maximal inbound delivery rate. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="smtpd_per_record_deadline">smtpd_per_record_deadline</a>
(default: normal: no, overload: yes)</b></DT><DD>
<p> Change the behavior of the <a href="postconf.5.html#smtpd_timeout">smtpd_timeout</a> and <a href="postconf.5.html#smtpd_starttls_timeout">smtpd_starttls_timeout</a>
time limits, from a
time limit per read or write system call, to a time limit to send
or receive a complete record (an SMTP command line, SMTP response
line, SMTP message content line, or TLS protocol message). This
limits the impact from hostile peers that trickle data one byte at
a time. </p>
<p> Note: when per-record deadlines are enabled, a short timeout
may cause problems with TLS over very slow network connections.
The reasons are that a TLS protocol message can be up to 16 kbytes
long (with TLSv1), and that an entire TLS protocol message must be
sent or received within the per-record deadline. </p>
<p> This feature is available in Postfix 2.9 and later. With older
Postfix releases, the behavior is as if this parameter is set to
"no". </p>
</DD>
<DT><b><a name="smtpd_policy_service_default_action">smtpd_policy_service_default_action</a>
(default: 451 4.3.5 Server configuration problem)</b></DT><DD>
<p> The default action when an SMTPD policy service request fails.
Specify "DUNNO" to behave as if the failed SMTPD policy service
request was not sent, and to continue processing other access
restrictions, if any. </p>
<p> Limitations: </p>
<ul>
<li> <p> This parameter may specify any value that would be a valid
SMTPD policy server response (or <a href="access.5.html">access(5)</a> map lookup result). An
<a href="access.5.html">access(5)</a> map or policy server in this parameter value may need to
be declared in advance with a restriction_class setting. </p>
<li> <p> If the specified action invokes another <a href="postconf.5.html#check_policy_service">check_policy_service</a>
request, that request will have the built-in default action. </p>
</ul>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="smtpd_policy_service_max_idle">smtpd_policy_service_max_idle</a>
(default: 300s)</b></DT><DD>
<p>
The time after which an idle SMTPD policy service connection is
closed.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="smtpd_policy_service_max_ttl">smtpd_policy_service_max_ttl</a>
(default: 1000s)</b></DT><DD>
<p>
The time after which an active SMTPD policy service connection is
closed.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="smtpd_policy_service_policy_context">smtpd_policy_service_policy_context</a>
(default: empty)</b></DT><DD>
<p> Optional information that the Postfix SMTP server specifies in
the "policy_context" attribute of a policy service request (originally,
to share the same service endpoint among multiple <a href="postconf.5.html#check_policy_service">check_policy_service</a>
clients). </p>
<p>
This feature is available in Postfix 3.1 and later.
</p>
</DD>
<DT><b><a name="smtpd_policy_service_request_limit">smtpd_policy_service_request_limit</a>
(default: 0)</b></DT><DD>
<p>
The maximal number of requests per SMTPD policy service connection,
or zero (no limit). Once a connection reaches this limit, the
connection is closed and the next request will be sent over a new
connection. This is a workaround to avoid error-recovery delays
with policy servers that cannot maintain a persistent connection.
</p>
<p>
This feature is available in Postfix 3.0 and later.
</p>
</DD>
<DT><b><a name="smtpd_policy_service_retry_delay">smtpd_policy_service_retry_delay</a>
(default: 1s)</b></DT><DD>
<p> The delay between attempts to resend a failed SMTPD policy
service request. Specify a value greater than zero. </p>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="smtpd_policy_service_timeout">smtpd_policy_service_timeout</a>
(default: 100s)</b></DT><DD>
<p>
The time limit for connecting to, writing to, or receiving from a
delegated SMTPD policy server.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="smtpd_policy_service_try_limit">smtpd_policy_service_try_limit</a>
(default: 2)</b></DT><DD>
<p> The maximal number of attempts to send an SMTPD policy service
request before giving up. Specify a value greater than zero. </p>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="smtpd_proxy_ehlo">smtpd_proxy_ehlo</a>
(default: $<a href="postconf.5.html#myhostname">myhostname</a>)</b></DT><DD>
<p>
How the Postfix SMTP server announces itself to the proxy filter.
By default, the Postfix hostname is used.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="smtpd_proxy_filter">smtpd_proxy_filter</a>
(default: empty)</b></DT><DD>
<p> The hostname and TCP port of the mail filtering proxy server.
The proxy receives all mail from the Postfix SMTP server, and is
supposed to give the result to another Postfix SMTP server process.
</p>
<p> Specify "host:port" or "inet:host:port" for a TCP endpoint, or
"unix:pathname" for a UNIX-domain endpoint. The host can be specified
as an IP address or as a symbolic name; no MX lookups are done.
When no "host" or "host:" are specified, the local machine is
assumed. Pathname interpretation is relative to the Postfix queue
directory. </p>
<p> This feature is available in Postfix 2.1 and later. </p>
<p> The "inet:" and "unix:" prefixes are available in Postfix 2.3
and later. </p>
</DD>
<DT><b><a name="smtpd_proxy_options">smtpd_proxy_options</a>
(default: empty)</b></DT><DD>
<p>
List of options that control how the Postfix SMTP server
communicates with a before-queue content filter. Specify zero or
more of the following, separated by comma or whitespace. </p>
<dl>
<dt><b>speed_adjust</b></dt>
<dd> <p> Do not connect to a before-queue content filter until an entire
message has been received. This reduces the number of simultaneous
before-queue content filter processes. </p>
<p> NOTE 1: A filter must not <i>selectively</i> reject recipients
of a multi-recipient message. Rejecting all recipients is OK, as
is accepting all recipients. </p>
<p> NOTE 2: This feature increases the minimum amount of free queue
space by $<a href="postconf.5.html#message_size_limit">message_size_limit</a>. The extra space is needed to save the
message to a temporary file. </p> </dd>
</dl>
<p>
This feature is available in Postfix 2.7 and later.
</p>
</DD>
<DT><b><a name="smtpd_proxy_timeout">smtpd_proxy_timeout</a>
(default: 100s)</b></DT><DD>
<p>
The time limit for connecting to a proxy filter and for sending or
receiving information. When a connection fails the client gets a
generic error message while more detailed information is logged to
the maillog file.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="smtpd_recipient_limit">smtpd_recipient_limit</a>
(default: 1000)</b></DT><DD>
<p>
The maximal number of recipients that the Postfix SMTP server
accepts per message delivery request.
</p>
</DD>
<DT><b><a name="smtpd_recipient_overshoot_limit">smtpd_recipient_overshoot_limit</a>
(default: 1000)</b></DT><DD>
<p> The number of recipients that a remote SMTP client can send in
excess of the limit specified with $<a href="postconf.5.html#smtpd_recipient_limit">smtpd_recipient_limit</a>, before
the Postfix SMTP server increments the per-session error count
for each excess recipient. </p>
</DD>
<DT><b><a name="smtpd_recipient_restrictions">smtpd_recipient_restrictions</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
Optional restrictions that the Postfix SMTP server applies in the
context of a client RCPT TO command, after <a href="postconf.5.html#smtpd_relay_restrictions">smtpd_relay_restrictions</a>.
See <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, section "Delayed evaluation of SMTP access
restriction lists" for a discussion of evaluation context and time.
</p>
<p> With Postfix versions before 2.10, the rules for relay permission
and spam blocking were combined under <a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a>,
resulting in error-prone configuration. As of Postfix 2.10, relay
permission rules are preferably implemented with <a href="postconf.5.html#smtpd_relay_restrictions">smtpd_relay_restrictions</a>,
so that a permissive spam blocking policy under
<a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> will no longer result in a permissive
mail relay policy. </p>
<p> For backwards compatibility, sites that migrate from Postfix
versions before 2.10 can set <a href="postconf.5.html#smtpd_relay_restrictions">smtpd_relay_restrictions</a> to the empty
value, and use <a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> exactly as before. </p>
<p>
IMPORTANT: Either the <a href="postconf.5.html#smtpd_relay_restrictions">smtpd_relay_restrictions</a> or the
<a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> parameter must specify
at least one of the following restrictions. Otherwise Postfix will
refuse to receive mail:
</p>
<blockquote>
<pre>
reject, <a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a>
</pre>
</blockquote>
<blockquote>
<pre>
defer, <a href="postconf.5.html#defer_if_permit">defer_if_permit</a>, <a href="postconf.5.html#defer_unauth_destination">defer_unauth_destination</a>
</pre>
</blockquote>
<p>
Specify a list of restrictions, separated by commas and/or whitespace.
Continue long lines by starting the next line with whitespace.
Restrictions are applied in the order as specified; the first
restriction that matches wins.
</p>
<p>
The following restrictions are specific to the recipient address
that is received with the RCPT TO command.
</p>
<dl>
<dt><b><a name="check_recipient_access">check_recipient_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd>Search the specified <a href="access.5.html">access(5)</a> database for the resolved RCPT
TO address, domain, parent domains, or localpart@, and execute the
corresponding action. </dd>
<dt><b><a name="check_recipient_a_access">check_recipient_a_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd>Search the specified <a href="access.5.html">access(5)</a> database for the IP addresses for
the RCPT TO domain, and execute the corresponding action. Note:
a result of "OK" is not allowed for safety reasons. Instead, use
DUNNO in order to exclude specific hosts from blacklists. This
feature is available in Postfix 3.0 and later. </dd>
<dt><b><a name="check_recipient_mx_access">check_recipient_mx_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd>Search the specified <a href="access.5.html">access(5)</a> database for the MX hosts for
the RCPT TO domain, and execute the corresponding action. Note:
a result of "OK" is not allowed for safety reasons. Instead, use
DUNNO in order to exclude specific hosts from blacklists. This
feature is available in Postfix 2.1 and later. </dd>
<dt><b><a name="check_recipient_ns_access">check_recipient_ns_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd>Search the specified <a href="access.5.html">access(5)</a> database for the DNS servers
for the RCPT TO domain, and execute the corresponding action.
Note: a result of "OK" is not allowed for safety reasons. Instead,
use DUNNO in order to exclude specific hosts from blacklists. This
feature is available in Postfix 2.1 and later. </dd>
<dt><b><a name="permit_auth_destination">permit_auth_destination</a></b></dt>
<dd>Permit the request when one of the following is true:
<ul>
<li> Postfix is mail forwarder: the resolved RCPT TO domain matches
$<a href="postconf.5.html#relay_domains">relay_domains</a> or a subdomain thereof, and the address contains no
sender-specified routing (user@elsewhere@domain),
<li> Postfix is the final destination: the resolved RCPT TO domain
matches $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>, $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>,
$<a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a>, or $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>, and the address
contains no sender-specified routing (user@elsewhere@domain).
</ul></dd>
<dt><b><a name="permit_mx_backup">permit_mx_backup</a></b></dt>
<dd>Permit the request when the local mail system is backup MX for
the RCPT TO domain, or when the domain is an authorized destination
(see <a href="postconf.5.html#permit_auth_destination">permit_auth_destination</a> for definition).
<ul>
<li> Safety: <a href="postconf.5.html#permit_mx_backup">permit_mx_backup</a> does not accept addresses that have
sender-specified routing information (example: user@elsewhere@domain).
<li> Safety: <a href="postconf.5.html#permit_mx_backup">permit_mx_backup</a> can be vulnerable to mis-use when
access is not restricted with <a href="postconf.5.html#permit_mx_backup_networks">permit_mx_backup_networks</a>.
<li> Safety: as of Postfix version 2.3, <a href="postconf.5.html#permit_mx_backup">permit_mx_backup</a> no longer
accepts the address when the local mail system is primary MX for
the recipient domain. Exception: <a href="postconf.5.html#permit_mx_backup">permit_mx_backup</a> accepts the address
when it specifies an authorized destination (see <a href="postconf.5.html#permit_auth_destination">permit_auth_destination</a>
for definition).
<li> Limitation: mail may be rejected in case of a temporary DNS
lookup problem with Postfix prior to version 2.0.
</ul></dd>
<dt><b><a name="reject_non_fqdn_recipient">reject_non_fqdn_recipient</a></b></dt>
<dd>Reject the request when the RCPT TO address specifies a
domain that is not in
fully-qualified domain form, as required by the RFC. <br> The
<a href="postconf.5.html#non_fqdn_reject_code">non_fqdn_reject_code</a> parameter specifies the response code for
rejected requests (default: 504). </dd>
<dt><b><a name="reject_rhsbl_recipient">reject_rhsbl_recipient <i>rbl_domain=d.d.d.d</i></a></b></dt>
<dd>Reject the request when the RCPT TO domain is listed with the
A record "<i>d.d.d.d</i>" under <i>rbl_domain</i> (Postfix version
2.1 and later only). Each "<i>d</i>" is a number, or a pattern
inside "[]" that contains one or more ";"-separated numbers or
number..number ranges (Postfix version 2.8 and later). If no
"<i>=d.d.d.d</i>" is specified, reject
the request when the RCPT TO domain is listed with
any A record under <i>rbl_domain</i>. <br> The <a href="postconf.5.html#maps_rbl_reject_code">maps_rbl_reject_code</a>
parameter specifies the response code for rejected requests (default:
554); the <a href="postconf.5.html#default_rbl_reply">default_rbl_reply</a> parameter specifies the default server
reply; and the <a href="postconf.5.html#rbl_reply_maps">rbl_reply_maps</a> parameter specifies tables with server
replies indexed by <i>rbl_domain</i>. This feature is available
in Postfix version 2.0 and later.</dd>
<dt><b><a name="reject_unauth_destination">reject_unauth_destination</a></b></dt>
<dd>Reject the request unless one of the following is true:
<ul>
<li> Postfix is mail forwarder: the resolved RCPT TO domain matches
$<a href="postconf.5.html#relay_domains">relay_domains</a> or a subdomain thereof, and contains no sender-specified
routing (user@elsewhere@domain),
<li> Postfix is the final destination: the resolved RCPT TO domain
matches $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>, $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>,
$<a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a>, or $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>, and contains
no sender-specified routing (user@elsewhere@domain).
</ul>The <a href="postconf.5.html#relay_domains_reject_code">relay_domains_reject_code</a> parameter specifies the response
code for rejected requests (default: 554). </dd>
<dt><b><a name="defer_unauth_destination">defer_unauth_destination</a></b></dt>
<dd> Reject the same requests as <a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a>, with a
non-permanent error code. This feature is available in Postfix
2.10 and later.</dd>
<dt><b><a name="reject_unknown_recipient_domain">reject_unknown_recipient_domain</a></b></dt>
<dd>Reject the request when Postfix is not final destination for
the recipient domain, and the RCPT TO domain has 1) no DNS MX and
no DNS A
record or 2) a malformed MX record such as a record with
a zero-length MX hostname (Postfix version 2.3 and later). <br> The
reply is specified with the <a href="postconf.5.html#unknown_address_reject_code">unknown_address_reject_code</a> parameter
(default: 450), <a href="postconf.5.html#unknown_address_tempfail_action">unknown_address_tempfail_action</a> (default:
<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>), or 556 (nullmx, Postfix 3.0 and
later). See the respective parameter descriptions for details.
</dd>
<dt><b><a name="reject_unlisted_recipient">reject_unlisted_recipient</a></b> (with Postfix version 2.0: check_recipient_maps)</dt>
<dd> Reject the request when the RCPT TO address is not listed in
the list of valid recipients for its domain class. See the
<a href="postconf.5.html#smtpd_reject_unlisted_recipient">smtpd_reject_unlisted_recipient</a> parameter description for details.
This feature is available in Postfix 2.1 and later.</dd>
<dt><b><a name="reject_unverified_recipient">reject_unverified_recipient</a></b></dt>
<dd>Reject the request when mail to the RCPT TO address is known
to bounce, or when the recipient address destination is not reachable.
Address verification information is managed by the <a href="verify.8.html">verify(8)</a> server;
see the <a href="ADDRESS_VERIFICATION_README.html">ADDRESS_VERIFICATION_README</a> file for details. <br> The
<a href="postconf.5.html#unverified_recipient_reject_code">unverified_recipient_reject_code</a> parameter specifies the numerical
response code when an address is known to bounce (default: 450,
change into 550 when you are confident that it is safe to do so).
<br>The <a href="postconf.5.html#unverified_recipient_defer_code">unverified_recipient_defer_code</a> parameter specifies the
numerical response code when an address probe failed due to a
temporary problem (default: 450). <br> The
<a href="postconf.5.html#unverified_recipient_tempfail_action">unverified_recipient_tempfail_action</a> parameter specifies the action
after address probe failure due to a temporary problem (default:
<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>). <br> This feature breaks for aliased addresses
with "<a href="postconf.5.html#enable_original_recipient">enable_original_recipient</a> = no" (Postfix ≤ 3.2). <br>
This feature is available in Postfix 2.1 and later. </dd>
</dl>
<p>
Other restrictions that are valid in this context:
</p>
<ul>
<li><a href="#generic">Generic</a> restrictions that can be used
in any SMTP command context, described under <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>.
<li>SMTP command specific restrictions described under
<a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>, <a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a> and
<a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a>.
</ul>
<p>
Example:
</p>
<pre>
# The Postfix before 2.10 default mail relay policy. Later Postfix
# versions implement this preferably with <a href="postconf.5.html#smtpd_relay_restrictions">smtpd_relay_restrictions</a>.
<a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> = <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>, <a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a>
</pre>
</DD>
<DT><b><a name="smtpd_reject_footer">smtpd_reject_footer</a>
(default: empty)</b></DT><DD>
<p> Optional information that is appended after each Postfix SMTP
server
4XX or 5XX response. </p>
<p> The following example uses "\c" at the start of the template
(supported in Postfix 2.10 and later) to suppress the line break
between the reply text and the footer text. With earlier Postfix
versions, the footer text always begins on a new line, and the "\c"
is output literally. </p>
<pre>
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
<a href="postconf.5.html#smtpd_reject_footer">smtpd_reject_footer</a> = \c. For assistance, call 800-555-0101.
Please provide the following information in your problem report:
time ($localtime), client ($client_address) and server
($server_name).
</pre>
<p> Server response: </p>
<pre>
550-5.5.1 <user@example> Recipient address rejected: User
unknown. For assistance, call 800-555-0101. Please provide the
following information in your problem report: time (Jan 4 15:42:00),
client (192.168.1.248) and server (mail1.example.com).
</pre>
<p> Note: the above text is meant to make it easier to find the
Postfix logfile records for a failed SMTP session. The text itself
is not logged to the Postfix SMTP server's maillog file. </p>
<p> Be sure to keep the text as short as possible. Long text may
be truncated before it is logged to the remote SMTP client's maillog
file, or before it is returned to the sender in a delivery status
notification. </p>
<p> This feature supports a limited number of $name attributes in
the footer text. These are replaced by their current value for the
SMTP session: </p>
<dl>
<dt> <b>client_address</b> </dt> <dd> The Client IP address that
is logged in the maillog file. </dd>
<dt> <b>client_port</b> </dt> <dd> The client TCP port that is
logged in the maillog file. </dd>
<dt> <b>localtime</b> </dt> <dd> The server local time (Mmm dd
hh:mm:ss) that is logged in the maillog file. </dd>
<dt> <b>server_name</b> </dt> <dd> The server's <a href="postconf.5.html#myhostname">myhostname</a> value.
This attribute is made available for sites with multiple MTAs
(perhaps behind a load-balancer), where the server name can help
the server support team to quickly find the right log files. </dd>
</dl>
<p> Notes: </p>
<ul>
<li> <p> NOT SUPPORTED are other attributes such as sender, recipient,
or <a href="postconf.5.html">main.cf</a> parameters. </p>
<li> <p> For safety reasons, text that does not match
$<a href="postconf.5.html#smtpd_expansion_filter">smtpd_expansion_filter</a> is censored. </p>
</ul>
<p> This feature supports the two-character sequence \n as a request
for a line break in the footer text. Postfix automatically inserts
after each line break the three-digit SMTP reply code (and optional
enhanced status code) from the original Postfix reject message.
</p>
<p> To work around mail software that mis-handles multi-line replies,
specify the two-character sequence \c at the start of the template.
This suppresses the line break between the reply text and the footer
text (Postfix 2.10 and later). </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="smtpd_reject_unlisted_recipient">smtpd_reject_unlisted_recipient</a>
(default: yes)</b></DT><DD>
<p>
Request that the Postfix SMTP server rejects mail for unknown
recipient addresses, even when no explicit <a href="postconf.5.html#reject_unlisted_recipient">reject_unlisted_recipient</a>
access restriction is specified. This prevents the Postfix queue
from filling up with undeliverable MAILER-DAEMON messages.
</p>
<p> An address is always considered "known" when it matches a
<a href="virtual.5.html">virtual(5)</a> alias or a <a href="canonical.5.html">canonical(5)</a> mapping.
<ul>
<li> The recipient domain matches $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>
or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>, but the recipient is not listed in
$<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a>, and $<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> is not null.
<li> The recipient domain matches $<a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a> but the
recipient is not listed in $<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a>.
<li> The recipient domain matches $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a> but the
recipient is not listed in $<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a>, and $<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a>
is not null.
<li> The recipient domain matches $<a href="postconf.5.html#relay_domains">relay_domains</a> but the recipient
is not listed in $<a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a>, and $<a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a>
is not null.
</ul>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="smtpd_reject_unlisted_sender">smtpd_reject_unlisted_sender</a>
(default: no)</b></DT><DD>
<p> Request that the Postfix SMTP server rejects mail from unknown
sender addresses, even when no explicit <a href="postconf.5.html#reject_unlisted_sender">reject_unlisted_sender</a>
access restriction is specified. This can slow down an explosion
of forged mail from worms or viruses. </p>
<p> An address is always considered "known" when it matches a
<a href="virtual.5.html">virtual(5)</a> alias or a <a href="canonical.5.html">canonical(5)</a> mapping.
<ul>
<li> The sender domain matches $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> or
$<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>, but the sender is not listed in
$<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a>, and $<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> is not null.
<li> The sender domain matches $<a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a> but the sender
is not listed in $<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a>.
<li> The sender domain matches $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a> but the
sender is not listed in $<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a>, and $<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a>
is not null.
<li> The sender domain matches $<a href="postconf.5.html#relay_domains">relay_domains</a> but the sender is
not listed in $<a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a>, and $<a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a> is
not null.
</ul>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="smtpd_relay_restrictions">smtpd_relay_restrictions</a>
(default: <a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>, <a href="postconf.5.html#permit_sasl_authenticated">permit_sasl_authenticated</a>, <a href="postconf.5.html#defer_unauth_destination">defer_unauth_destination</a>)</b></DT><DD>
<p> Access restrictions for mail relay control that the Postfix
SMTP server applies in the context of the RCPT TO command, before
<a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a>.
See <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, section "Delayed evaluation of SMTP access
restriction lists" for a discussion of evaluation context and time.
</p>
<p> With Postfix versions before 2.10, the rules for relay permission
and spam blocking were combined under <a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a>,
resulting in error-prone configuration. As of Postfix 2.10, relay
permission rules are preferably implemented with <a href="postconf.5.html#smtpd_relay_restrictions">smtpd_relay_restrictions</a>,
so that a permissive spam blocking policy under
<a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> will no longer result in a permissive
mail relay policy. </p>
<p> For backwards compatibility, sites that migrate from Postfix
versions before 2.10 can set <a href="postconf.5.html#smtpd_relay_restrictions">smtpd_relay_restrictions</a> to the empty
value, and use <a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> exactly as before. </p>
<p>
By default, the Postfix SMTP server accepts:
</p>
<ul>
<li> Mail from clients whose IP address matches $<a href="postconf.5.html#mynetworks">mynetworks</a>, or:
<li> Mail to remote destinations that match $<a href="postconf.5.html#relay_domains">relay_domains</a>, except
for addresses that contain sender-specified routing
(user@elsewhere@domain), or:
<li> Mail to local destinations that match $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>
or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>, $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a>, or
$<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>.
</ul>
<p>
IMPORTANT: Either the <a href="postconf.5.html#smtpd_relay_restrictions">smtpd_relay_restrictions</a> or the
<a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> parameter must specify
at least one of the following restrictions. Otherwise Postfix will
refuse to receive mail:
</p>
<blockquote>
<pre>
reject, <a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a>
</pre>
</blockquote>
<blockquote>
<pre>
defer, <a href="postconf.5.html#defer_if_permit">defer_if_permit</a>, <a href="postconf.5.html#defer_unauth_destination">defer_unauth_destination</a>
</pre>
</blockquote>
<p>
Specify a list of restrictions, separated by commas and/or whitespace.
Continue long lines by starting the next line with whitespace.
The same restrictions are available as documented under
<a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a>.
</p>
<p> This feature is available in Postix 2.10 and later. </p>
</DD>
<DT><b><a name="smtpd_restriction_classes">smtpd_restriction_classes</a>
(default: empty)</b></DT><DD>
<p>
User-defined aliases for groups of access restrictions. The aliases
can be specified in <a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> etc., and on the
right-hand side of a Postfix <a href="access.5.html">access(5)</a> table.
</p>
<p>
One major application is for implementing per-recipient UCE control.
See the <a href="RESTRICTION_CLASS_README.html">RESTRICTION_CLASS_README</a> document for other examples.
</p>
</DD>
<DT><b><a name="smtpd_sasl_application_name">smtpd_sasl_application_name</a>
(default: smtpd)</b></DT><DD>
<p>
The application name that the Postfix SMTP server uses for SASL
server initialization. This
controls the name of the SASL configuration file. The default value
is <b>smtpd</b>, corresponding to a SASL configuration file named
<b>smtpd.conf</b>.
</p>
<p>
This feature is available in Postfix 2.1 and 2.2. With Postfix 2.3
it was renamed to <a href="postconf.5.html#smtpd_sasl_path">smtpd_sasl_path</a>.
</p>
</DD>
<DT><b><a name="smtpd_sasl_auth_enable">smtpd_sasl_auth_enable</a>
(default: no)</b></DT><DD>
<p>
Enable SASL authentication in the Postfix SMTP server. By default,
the Postfix SMTP server does not use authentication.
</p>
<p>
If a remote SMTP client is authenticated, the <a href="postconf.5.html#permit_sasl_authenticated">permit_sasl_authenticated</a>
access restriction can be used to permit relay access, like this:
</p>
<blockquote>
<pre>
# With Postfix 2.10 and later, the mail relay policy is
# preferably specified under <a href="postconf.5.html#smtpd_relay_restrictions">smtpd_relay_restrictions</a>.
<a href="postconf.5.html#smtpd_relay_restrictions">smtpd_relay_restrictions</a> =
<a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>, <a href="postconf.5.html#permit_sasl_authenticated">permit_sasl_authenticated</a>, ...
</pre>
<pre>
# With Postfix before 2.10, the relay policy can be
# specified only under <a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a>.
<a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> =
<a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>, <a href="postconf.5.html#permit_sasl_authenticated">permit_sasl_authenticated</a>, ...
</pre>
</blockquote>
<p> To reject all SMTP connections from unauthenticated clients,
specify "<a href="postconf.5.html#smtpd_delay_reject">smtpd_delay_reject</a> = yes" (which is the default) and use:
</p>
<blockquote>
<pre>
<a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> = <a href="postconf.5.html#permit_sasl_authenticated">permit_sasl_authenticated</a>, reject
</pre>
</blockquote>
<p>
See the <a href="SASL_README.html">SASL_README</a> file for SASL configuration and operation details.
</p>
</DD>
<DT><b><a name="smtpd_sasl_authenticated_header">smtpd_sasl_authenticated_header</a>
(default: no)</b></DT><DD>
<p> Report the SASL authenticated user name in the <a href="smtpd.8.html">smtpd(8)</a> Received
message header. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="smtpd_sasl_exceptions_networks">smtpd_sasl_exceptions_networks</a>
(default: empty)</b></DT><DD>
<p>
What remote SMTP clients the Postfix SMTP server will not offer
AUTH support to.
</p>
<p>
Some clients (Netscape 4 at least) have a bug that causes them to
require a login and password whenever AUTH is offered, whether it's
necessary or not. To work around this, specify, for example,
$<a href="postconf.5.html#mynetworks">mynetworks</a> to prevent Postfix from offering AUTH to local clients.
</p>
<p>
Specify a list of network/netmask patterns, separated by commas
and/or whitespace. The mask specifies the number of bits in the
network part of a host address. You can also "/file/name" or
"<a href="DATABASE_README.html">type:table</a>" patterns. A "/file/name" pattern is replaced by its
contents; a "<a href="DATABASE_README.html">type:table</a>" lookup table is matched when a table entry
matches a lookup string (the lookup result is ignored). Continue
long lines by starting the next line with whitespace. Specify
"!pattern" to exclude an address or network block from the list.
The form "!/file/name" is supported only in Postfix version 2.4 and
later. </p>
<p> Note: IP version 6 address information must be specified inside
<tt>[]</tt> in the <a href="postconf.5.html#smtpd_sasl_exceptions_networks">smtpd_sasl_exceptions_networks</a> value, and in
files specified with "/file/name". IP version 6 addresses contain
the ":" character, and would otherwise be confused with a "<a href="DATABASE_README.html">type:table</a>"
pattern. </p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#smtpd_sasl_exceptions_networks">smtpd_sasl_exceptions_networks</a> = $<a href="postconf.5.html#mynetworks">mynetworks</a>
</pre>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="smtpd_sasl_local_domain">smtpd_sasl_local_domain</a>
(default: empty)</b></DT><DD>
<p>
The name of the Postfix SMTP server's local SASL authentication
realm.
</p>
<p>
By default, the local authentication realm name is the null string.
</p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#smtpd_sasl_local_domain">smtpd_sasl_local_domain</a> = $<a href="postconf.5.html#mydomain">mydomain</a>
<a href="postconf.5.html#smtpd_sasl_local_domain">smtpd_sasl_local_domain</a> = $<a href="postconf.5.html#myhostname">myhostname</a>
</pre>
</DD>
<DT><b><a name="smtpd_sasl_path">smtpd_sasl_path</a>
(default: smtpd)</b></DT><DD>
<p> Implementation-specific information that the Postfix SMTP server
passes through to
the SASL plug-in implementation that is selected with
<b><a href="postconf.5.html#smtpd_sasl_type">smtpd_sasl_type</a></b>. Typically this specifies the name of a
configuration file or rendezvous point. </p>
<p> This feature is available in Postfix 2.3 and later. In earlier
releases it was called <b><a href="postconf.5.html#smtpd_sasl_application_name">smtpd_sasl_application_name</a></b>. </p>
</DD>
<DT><b><a name="smtpd_sasl_security_options">smtpd_sasl_security_options</a>
(default: noanonymous)</b></DT><DD>
<p> Postfix SMTP server SASL security options; as of Postfix 2.3
the list of available
features depends on the SASL server implementation that is selected
with <b><a href="postconf.5.html#smtpd_sasl_type">smtpd_sasl_type</a></b>. </p>
<p> The following security features are defined for the <b>cyrus</b>
server SASL implementation: </p>
<p>
Restrict what authentication mechanisms the Postfix SMTP server
will offer to the client. The list of available authentication
mechanisms is system dependent.
</p>
<p>
Specify zero or more of the following:
</p>
<dl>
<dt><b>noplaintext</b></dt>
<dd>Disallow methods that use plaintext passwords. </dd>
<dt><b>noactive</b></dt>
<dd>Disallow methods subject to active (non-dictionary) attack. </dd>
<dt><b>nodictionary</b></dt>
<dd>Disallow methods subject to passive (dictionary) attack. </dd>
<dt><b>noanonymous</b></dt>
<dd>Disallow methods that allow anonymous authentication. </dd>
<dt><b>forward_secrecy</b></dt>
<dd>Only allow methods that support forward secrecy (Dovecot only).
</dd>
<dt><b>mutual_auth</b></dt>
<dd>Only allow methods that provide mutual authentication (not available
with Cyrus SASL version 1). </dd>
</dl>
<p>
By default, the Postfix SMTP server accepts plaintext passwords but
not anonymous logins.
</p>
<p>
Warning: it appears that clients try authentication methods in the
order as advertised by the server (e.g., PLAIN ANONYMOUS CRAM-MD5)
which means that if you disable plaintext passwords, clients will
log in anonymously, even when they should be able to use CRAM-MD5.
So, if you disable plaintext logins, disable anonymous logins too.
Postfix treats anonymous login as no authentication.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#smtpd_sasl_security_options">smtpd_sasl_security_options</a> = noanonymous, noplaintext
</pre>
</DD>
<DT><b><a name="smtpd_sasl_service">smtpd_sasl_service</a>
(default: smtp)</b></DT><DD>
<p> The service name that is passed to the SASL plug-in that is
selected with <b><a href="postconf.5.html#smtpd_sasl_type">smtpd_sasl_type</a></b> and <b><a href="postconf.5.html#smtpd_sasl_path">smtpd_sasl_path</a></b>.
</p>
<p> This feature is available in Postfix 2.11 and later. Prior
versions behave as if "<b>smtp</b>" is specified. </p>
</DD>
<DT><b><a name="smtpd_sasl_tls_security_options">smtpd_sasl_tls_security_options</a>
(default: $<a href="postconf.5.html#smtpd_sasl_security_options">smtpd_sasl_security_options</a>)</b></DT><DD>
<p> The SASL authentication security options that the Postfix SMTP
server uses for TLS encrypted SMTP sessions. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtpd_sasl_type">smtpd_sasl_type</a>
(default: cyrus)</b></DT><DD>
<p> The SASL plug-in type that the Postfix SMTP server should use
for authentication. The available types are listed with the
"<b>postconf -a</b>" command. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="smtpd_sender_login_maps">smtpd_sender_login_maps</a>
(default: empty)</b></DT><DD>
<p>
Optional lookup table with the SASL login names that own the sender
(MAIL FROM) addresses.
</p>
<p>
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found. With lookups from
indexed files such as DB or DBM, or from networked tables such as
NIS, LDAP or SQL, the following search operations are done with a
sender address of <i>user@domain</i>: </p>
<dl>
<dt> 1) <i>user@domain</i> </dt>
<dd>This table lookup is always done and has the highest precedence. </dd>
<dt> 2) <i>user</i> </dt>
<dd>This table lookup is done only when the <i>domain</i> part of the
sender address matches $<a href="postconf.5.html#myorigin">myorigin</a>, $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>
or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>. </dd>
<dt> 3) <i>@domain</i> </dt>
<dd>This table lookup is done last and has the lowest precedence. </dd>
</dl>
<p>
In all cases the result of table lookup must be either "not found"
or a list of SASL login names separated by comma and/or whitespace.
</p>
</DD>
<DT><b><a name="smtpd_sender_restrictions">smtpd_sender_restrictions</a>
(default: empty)</b></DT><DD>
<p>
Optional restrictions that the Postfix SMTP server applies in the
context of a client MAIL FROM command.
See <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, section "Delayed evaluation of SMTP access
restriction lists" for a discussion of evaluation context and time.
</p>
<p>
The default is to permit everything.
</p>
<p>
Specify a list of restrictions, separated by commas and/or whitespace.
Continue long lines by starting the next line with whitespace.
Restrictions are applied in the order as specified; the first
restriction that matches wins.
</p>
<p>
The following restrictions are specific to the sender address
received with the MAIL FROM command.
</p>
<dl>
<dt><b><a name="check_sender_access">check_sender_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd>Search the specified <a href="access.5.html">access(5)</a> database for the MAIL FROM
address, domain, parent domains, or localpart@, and execute the
corresponding action. </dd>
<dt><b><a name="check_sender_a_access">check_sender_a_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd>Search the specified <a href="access.5.html">access(5)</a> database for the IP addresses for
the MAIL FROM domain, and execute the corresponding action. Note:
a result of "OK" is not allowed for safety reasons. Instead, use
DUNNO in order to exclude specific hosts from blacklists. This
feature is available in Postfix 3.0 and later. </dd>
<dt><b><a name="check_sender_mx_access">check_sender_mx_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd>Search the specified <a href="access.5.html">access(5)</a> database for the MX hosts for
the MAIL FROM domain, and execute the corresponding action. Note:
a result of "OK" is not allowed for safety reasons. Instead, use
DUNNO in order to exclude specific hosts from blacklists. This
feature is available in Postfix 2.1 and later. </dd>
<dt><b><a name="check_sender_ns_access">check_sender_ns_access</a> <i><a href="DATABASE_README.html">type:table</a></i></b></dt>
<dd>Search the specified <a href="access.5.html">access(5)</a> database for the DNS servers
for the MAIL FROM domain, and execute the corresponding action.
Note: a result of "OK" is not allowed for safety reasons. Instead,
use DUNNO in order to exclude specific hosts from blacklists. This
feature is available in Postfix 2.1 and later. </dd>
<dt><b><a name="reject_authenticated_sender_login_mismatch">reject_authenticated_sender_login_mismatch</a></b></dt>
<dd>Enforces the <a href="postconf.5.html#reject_sender_login_mismatch">reject_sender_login_mismatch</a> restriction for
authenticated clients only. This feature is available in
Postfix version 2.1 and later. </dd>
<dt><b><a name="reject_known_sender_login_mismatch">reject_known_sender_login_mismatch</a></b></dt>
<dd>Apply the <a href="postconf.5.html#reject_sender_login_mismatch">reject_sender_login_mismatch</a> restriction only to MAIL
FROM addresses that are known in $<a href="postconf.5.html#smtpd_sender_login_maps">smtpd_sender_login_maps</a>. This
feature is available in Postfix version 2.11 and later. </dd>
<dt><b><a name="reject_non_fqdn_sender">reject_non_fqdn_sender</a></b></dt>
<dd>Reject the request when the MAIL FROM address specifies a
domain that is not in
fully-qualified domain form as required by the RFC. <br> The
<a href="postconf.5.html#non_fqdn_reject_code">non_fqdn_reject_code</a> parameter specifies the response code for
rejected requests (default: 504). </dd>
<dt><b><a name="reject_rhsbl_sender">reject_rhsbl_sender <i>rbl_domain=d.d.d.d</i></a></b></dt>
<dd>Reject the request when the MAIL FROM domain is listed with
the A record "<i>d.d.d.d</i>" under <i>rbl_domain</i> (Postfix
version 2.1 and later only). Each "<i>d</i>" is a number, or a
pattern inside "[]" that contains one or more ";"-separated numbers
or number..number ranges (Postfix version 2.8 and later). If no
"<i>=d.d.d.d</i>" is specified,
reject the request when the MAIL FROM domain is
listed with any A record under <i>rbl_domain</i>. <br> The
<a href="postconf.5.html#maps_rbl_reject_code">maps_rbl_reject_code</a> parameter specifies the response code for
rejected requests (default: 554); the <a href="postconf.5.html#default_rbl_reply">default_rbl_reply</a> parameter
specifies the default server reply; and the <a href="postconf.5.html#rbl_reply_maps">rbl_reply_maps</a> parameter
specifies tables with server replies indexed by <i>rbl_domain</i>.
This feature is available in Postfix 2.0 and later.</dd>
<dt><b><a name="reject_sender_login_mismatch">reject_sender_login_mismatch</a></b></dt>
<dd>Reject the request when $<a href="postconf.5.html#smtpd_sender_login_maps">smtpd_sender_login_maps</a> specifies an
owner for the MAIL FROM address, but the client is not (SASL) logged
in as that MAIL FROM address owner; or when the client is (SASL)
logged in, but the client login name doesn't own the MAIL FROM
address according to $<a href="postconf.5.html#smtpd_sender_login_maps">smtpd_sender_login_maps</a>.</dd>
<dt><b><a name="reject_unauthenticated_sender_login_mismatch">reject_unauthenticated_sender_login_mismatch</a></b></dt>
<dd>Enforces the <a href="postconf.5.html#reject_sender_login_mismatch">reject_sender_login_mismatch</a> restriction for
unauthenticated clients only. This feature is available in
Postfix version 2.1 and later. </dd>
<dt><b><a name="reject_unknown_sender_domain">reject_unknown_sender_domain</a></b></dt>
<dd>Reject the request when Postfix is not final destination for
the sender address, and the MAIL FROM domain has 1) no DNS MX and
no DNS A
record, or 2) a malformed MX record such as a record with
a zero-length MX hostname (Postfix version 2.3 and later). <br> The
reply is specified with the <a href="postconf.5.html#unknown_address_reject_code">unknown_address_reject_code</a> parameter
(default: 450), <a href="postconf.5.html#unknown_address_tempfail_action">unknown_address_tempfail_action</a> (default:
<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>), or 550 (nullmx, Postfix 3.0 and
later). See the respective parameter descriptions for details.
</dd>
<dt><b><a name="reject_unlisted_sender">reject_unlisted_sender</a></b></dt>
<dd>Reject the request when the MAIL FROM address is not listed in
the list of valid recipients for its domain class. See the
<a href="postconf.5.html#smtpd_reject_unlisted_sender">smtpd_reject_unlisted_sender</a> parameter description for details.
This feature is available in Postfix 2.1 and later.</dd>
<dt><b><a name="reject_unverified_sender">reject_unverified_sender</a></b></dt>
<dd>Reject the request when mail to the MAIL FROM address is known to
bounce, or when the sender address destination is not reachable.
Address verification information is managed by the <a href="verify.8.html">verify(8)</a> server;
see the <a href="ADDRESS_VERIFICATION_README.html">ADDRESS_VERIFICATION_README</a> file for details. <br> The
<a href="postconf.5.html#unverified_sender_reject_code">unverified_sender_reject_code</a> parameter specifies the numerical
response code when an address is known to bounce (default: 450,
change into 550 when you are confident that it is safe to do so).
<br>The <a href="postconf.5.html#unverified_sender_defer_code">unverified_sender_defer_code</a> specifies the numerical response
code when an address probe failed due to a temporary problem
(default: 450). <br> The <a href="postconf.5.html#unverified_sender_tempfail_action">unverified_sender_tempfail_action</a> parameter
specifies the action after address probe failure due to a temporary
problem (default: <a href="postconf.5.html#defer_if_permit">defer_if_permit</a>). <br> This feature breaks for
aliased addresses with "<a href="postconf.5.html#enable_original_recipient">enable_original_recipient</a> = no" (Postfix
≤ 3.2). <br> This feature is available in Postfix 2.1 and later.
</dd>
</dl>
<p>
Other restrictions that are valid in this context:
</p>
<ul>
<li> <a href="#generic">Generic</a> restrictions that can be used
in any SMTP command context, described under <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>.
<li> SMTP command specific restrictions described under
<a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> and <a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a>.
<li> SMTP command specific restrictions described under
<a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a>. When recipient restrictions are listed
under <a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a>, they have effect only with
"<a href="postconf.5.html#smtpd_delay_reject">smtpd_delay_reject</a> = yes", so that $<a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a> is
evaluated at the time of the RCPT TO command.
</ul>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a> = <a href="postconf.5.html#reject_unknown_sender_domain">reject_unknown_sender_domain</a>
<a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a> = <a href="postconf.5.html#reject_unknown_sender_domain">reject_unknown_sender_domain</a>,
<a href="postconf.5.html#check_sender_access">check_sender_access</a> <a href="DATABASE_README.html#types">hash</a>:/etc/postfix/access
</pre>
</DD>
<DT><b><a name="smtpd_service_name">smtpd_service_name</a>
(default: smtpd)</b></DT><DD>
<p> The internal service that <a href="postscreen.8.html">postscreen(8)</a> hands off allowed
connections to. In a future version there may be different
classes of SMTP service. </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="smtpd_soft_error_limit">smtpd_soft_error_limit</a>
(default: 10)</b></DT><DD>
<p>
The number of errors a remote SMTP client is allowed to make without
delivering mail before the Postfix SMTP server slows down all its
responses.
</p>
<ul>
<li><p>With Postfix version 2.1 and later, the Postfix SMTP server
delays all responses by $<a href="postconf.5.html#smtpd_error_sleep_time">smtpd_error_sleep_time</a> seconds. </p>
<li><p>With Postfix versions 2.0 and earlier, the Postfix SMTP
server delays all responses by (number of errors) seconds. </p>
</ul>
</DD>
<DT><b><a name="smtpd_starttls_timeout">smtpd_starttls_timeout</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> The time limit for Postfix SMTP server write and read operations
during TLS startup and shutdown handshake procedures. The current
default value is stress-dependent. Before Postfix version 2.8, it
was fixed at 300s. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtpd_timeout">smtpd_timeout</a>
(default: normal: 300s, overload: 10s)</b></DT><DD>
<p>
The time limit for sending a Postfix SMTP server response and for
receiving a remote SMTP client request. Normally the default limit
is 300s, but it changes under overload to just 10s. With Postfix
2.5 and earlier, the SMTP server always uses a time limit of 300s
by default.
</p>
<p>
Note: if you set SMTP time limits to very large values you may have
to update the global <a href="postconf.5.html#ipc_timeout">ipc_timeout</a> parameter.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="smtpd_tls_CAfile">smtpd_tls_CAfile</a>
(default: empty)</b></DT><DD>
<p> A file containing (PEM format) CA certificates of root CAs trusted
to sign either remote SMTP client certificates or intermediate CA
certificates. These are loaded into memory before the <a href="smtpd.8.html">smtpd(8)</a> server
enters the chroot jail. If the number of trusted roots is large, consider
using <a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a> instead, but note that the latter directory must
be present in the chroot jail if the <a href="smtpd.8.html">smtpd(8)</a> server is chrooted. This
file may also be used to augment the server certificate trust chain,
but it is best to include all the required certificates directly in the
server certificate file. </p>
<p> Specify "<a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a> = /path/to/system_CA_file" to use ONLY
the system-supplied default Certification Authority certificates.
</p>
<p> Specify "<a href="postconf.5.html#tls_append_default_CA">tls_append_default_CA</a> = no" to prevent Postfix from
appending the system-supplied default CAs and trusting third-party
certificates. </p>
<p> By default (see <a href="postconf.5.html#smtpd_tls_ask_ccert">smtpd_tls_ask_ccert</a>), client certificates are not
requested, and <a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a> should remain empty. If you do make use
of client certificates, the distinguished names (DNs) of the Certification
Authorities listed in <a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a> are sent to the remote SMTP client
in the client certificate request message. MUAs with multiple client
certificates may use the list of preferred Certification Authorities
to select the correct client certificate. You may want to put your
"preferred" CA or CAs in this file, and install other trusted CAs in
$<a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a>. </p>
<p> Example: </p>
<pre>
<a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a> = /etc/postfix/CAcert.pem
</pre>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtpd_tls_CApath">smtpd_tls_CApath</a>
(default: empty)</b></DT><DD>
<p> A directory containing (PEM format) CA certificates of root CAs
trusted to sign either remote SMTP client certificates or intermediate CA
certificates. Do not forget to create the necessary "hash" links with,
for example, "$OPENSSL_HOME/bin/c_rehash /etc/postfix/certs". To use
<a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a> in chroot mode, this directory (or a copy) must be
inside the chroot jail. </p>
<p> Specify "<a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a> = /path/to/system_CA_directory" to
use ONLY the system-supplied default Certification Authority certificates.
</p>
<p> Specify "<a href="postconf.5.html#tls_append_default_CA">tls_append_default_CA</a> = no" to prevent Postfix from
appending the system-supplied default CAs and trusting third-party
certificates. </p>
<p> By default (see <a href="postconf.5.html#smtpd_tls_ask_ccert">smtpd_tls_ask_ccert</a>), client certificates are
not requested, and <a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a> should remain empty. In contrast
to <a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a>, DNs of Certification Authorities installed
in $<a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a> are not included in the client certificate
request message. MUAs with multiple client certificates may use the
list of preferred Certification Authorities to select the correct
client certificate. You may want to put your "preferred" CA or
CAs in $<a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a>, and install the remaining trusted CAs in
$<a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a>. </p>
<p> Example: </p>
<pre>
<a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a> = /etc/postfix/certs
</pre>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtpd_tls_always_issue_session_ids">smtpd_tls_always_issue_session_ids</a>
(default: yes)</b></DT><DD>
<p> Force the Postfix SMTP server to issue a TLS session id, even
when TLS session caching is turned off (<a href="postconf.5.html#smtpd_tls_session_cache_database">smtpd_tls_session_cache_database</a>
is empty). This behavior is compatible with Postfix < 2.3. </p>
<p> With Postfix 2.3 and later the Postfix SMTP server can disable
session id generation when TLS session caching is turned off. This
keeps remote SMTP clients from caching sessions that almost certainly cannot
be re-used. </p>
<p> By default, the Postfix SMTP server always generates TLS session
ids. This works around a known defect in mail client applications
such as MS Outlook, and may also prevent interoperability issues
with other MTAs. </p>
<p> Example: </p>
<pre>
<a href="postconf.5.html#smtpd_tls_always_issue_session_ids">smtpd_tls_always_issue_session_ids</a> = no
</pre>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="smtpd_tls_ask_ccert">smtpd_tls_ask_ccert</a>
(default: no)</b></DT><DD>
<p> Ask a remote SMTP client for a client certificate. This
information is needed for certificate based mail relaying with,
for example, the <a href="postconf.5.html#permit_tls_clientcerts">permit_tls_clientcerts</a> feature. </p>
<p> Some clients such as Netscape will either complain if no
certificate is available (for the list of CAs in $<a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a>)
or will offer multiple client certificates to choose from. This
may be annoying, so this option is "off" by default. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtpd_tls_auth_only">smtpd_tls_auth_only</a>
(default: no)</b></DT><DD>
<p> When TLS encryption is optional in the Postfix SMTP server, do
not announce or accept SASL authentication over unencrypted
connections. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtpd_tls_ccert_verifydepth">smtpd_tls_ccert_verifydepth</a>
(default: 9)</b></DT><DD>
<p> The verification depth for remote SMTP client certificates. A
depth of 1 is sufficient if the issuing CA is listed in a local CA
file. </p>
<p> The default verification depth is 9 (the OpenSSL default) for
compatibility with earlier Postfix behavior. Prior to Postfix 2.5,
the default value was 5, but the limit was not actually enforced. If
you have set this to a lower non-default value, certificates with longer
trust chains may now fail to verify. Certificate chains with 1 or 2
CAs are common, deeper chains are more rare and any number between 5
and 9 should suffice in practice. You can choose a lower number if,
for example, you trust certificates directly signed by an issuing CA
but not any CAs it delegates to. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtpd_tls_cert_file">smtpd_tls_cert_file</a>
(default: empty)</b></DT><DD>
<p> File with the Postfix SMTP server RSA certificate in PEM format.
This file may also contain the Postfix SMTP server private RSA key. </p>
<p> Public Internet MX hosts without certificates signed by a "reputable"
CA must generate, and be prepared to present to most clients, a
self-signed or private-CA signed certificate. The client will not be
able to authenticate the server, but unless it is running Postfix 2.3 or
similar software, it will still insist on a server certificate. </p>
<p> For servers that are <b>not</b> public Internet MX hosts, Postfix
2.3 supports configurations with no certificates. This entails the
use of just the anonymous TLS ciphers, which are not supported by
typical SMTP clients. Since such clients will not, as a rule, fall
back to plain text after a TLS handshake failure, the server will
be unable to receive email from TLS enabled clients. To avoid
accidental configurations with no certificates, Postfix 2.3 enables
certificate-less operation only when the administrator explicitly
sets "<a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a> = none". This ensures that new Postfix
configurations will not accidentally run with no certificates. </p>
<p> Both RSA and DSA certificates are supported. When both types
are present, the cipher used determines which certificate will be
presented to the client. For Netscape and OpenSSL clients without
special cipher choices the RSA certificate is preferred. </p>
<p> To enable a remote SMTP client to verify the Postfix SMTP server
certificate, the issuing CA certificates must be made available to the
client. You should include the required certificates in the server
certificate file, the server certificate first, then the issuing
CA(s) (bottom-up order). </p>
<p> Example: the certificate for "server.example.com" was issued by
"intermediate CA" which itself has a certificate of "root CA".
Create the server.pem file with "cat server_cert.pem intermediate_CA.pem
root_CA.pem > server.pem". </p>
<p> If you also want to verify client certificates issued by these
CAs, you can add the CA certificates to the <a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a>, in which
case it is not necessary to have them in the <a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a> or
<a href="postconf.5.html#smtpd_tls_dcert_file">smtpd_tls_dcert_file</a>. </p>
<p> A certificate supplied here must be usable as an SSL server certificate
and hence pass the "openssl verify -purpose sslserver ..." test. </p>
<p> Example: </p>
<pre>
<a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a> = /etc/postfix/server.pem
</pre>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtpd_tls_cipherlist">smtpd_tls_cipherlist</a>
(default: empty)</b></DT><DD>
<p> Obsolete Postfix < 2.3 control for the Postfix SMTP server TLS
cipher list. It is easy to create interoperability problems by choosing
a non-default cipher list. Do not use a non-default TLS cipherlist for
MX hosts on the public Internet. Clients that begin the TLS handshake,
but are unable to agree on a common cipher, may not be able to send any
email to the SMTP server. Using a restricted cipher list may be more
appropriate for a dedicated MSA or an internal mailhub, where one can
exert some control over the TLS software and settings of the connecting
clients. </p>
<p> <b>Note:</b> do not use "" quotes around the parameter value. </p>
<p>This feature is available with Postfix version 2.2. It is not used with
Postfix 2.3 and later; use <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a> instead. </p>
</DD>
<DT><b><a name="smtpd_tls_ciphers">smtpd_tls_ciphers</a>
(default: medium)</b></DT><DD>
<p> The minimum TLS cipher grade that the Postfix SMTP server
will use with opportunistic TLS encryption. Cipher types listed in
<a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> are excluded from the base definition of
the selected cipher grade. The default value is "medium" for Postfix
releases after the middle of 2015, "export" for older releases.
</p>
<p> When TLS is mandatory the cipher grade is chosen via the
<a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a> configuration parameter, see there for syntax
details. </p>
<p> This feature is available in Postfix 2.6 and later. With earlier Postfix
releases only the <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a> parameter is implemented,
and opportunistic TLS always uses "export" or better (i.e. all) ciphers. </p>
</DD>
<DT><b><a name="smtpd_tls_dcert_file">smtpd_tls_dcert_file</a>
(default: empty)</b></DT><DD>
<p> File with the Postfix SMTP server DSA certificate in PEM format.
This file may also contain the Postfix SMTP server private DSA key. </p>
<p> See the discussion under <a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a> for more details.
</p>
<p> Example: </p>
<pre>
<a href="postconf.5.html#smtpd_tls_dcert_file">smtpd_tls_dcert_file</a> = /etc/postfix/server-dsa.pem
</pre>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtpd_tls_dh1024_param_file">smtpd_tls_dh1024_param_file</a>
(default: empty)</b></DT><DD>
<p> File with DH parameters that the Postfix SMTP server should
use with non-export EDH ciphers. </p>
<p> Instead of using the exact same parameter sets as distributed
with other TLS packages, it is more secure to generate your own
set of parameters with something like the following commands: </p>
<blockquote>
<pre>
openssl dhparam -out /etc/postfix/dh512.pem 512
openssl dhparam -out /etc/postfix/dh1024.pem 1024
openssl dhparam -out /etc/postfix/dh2048.pem 2048
</pre>
</blockquote>
<p> It is safe to share the same DH parameters between multiple
Postfix instances. If you prefer, you can generate separate
parameters for each instance. </p>
<p> If you want to take maximal advantage of ciphers that offer <a
href="FORWARD_SECRECY_README.html#dfn_fs">forward secrecy</a> see
the <a href="FORWARD_SECRECY_README.html#quick-start">Getting
started</a> section of <a
href="FORWARD_SECRECY_README.html">FORWARD_SECRECY_README</a>. The
full document conveniently presents all information about Postfix
"perfect" forward secrecy support in one place: what forward secrecy
is, how to tweak settings, and what you can expect to see when
Postfix uses ciphers with forward secrecy. </p>
<p> Example: </p>
<pre>
<a href="postconf.5.html#smtpd_tls_dh1024_param_file">smtpd_tls_dh1024_param_file</a> = /etc/postfix/dh2048.pem
</pre>
<p>This feature is available with Postfix version 2.2.</p>
</DD>
<DT><b><a name="smtpd_tls_dh512_param_file">smtpd_tls_dh512_param_file</a>
(default: empty)</b></DT><DD>
<p> File with DH parameters that the Postfix SMTP server should
use with export-grade EDH ciphers. The default SMTP server cipher
grade is "medium" with Postfix releases after the middle of 2015,
and as a result export-grade cipher suites are by default not used.
</p>
<p> See also the discussion under the <a href="postconf.5.html#smtpd_tls_dh1024_param_file">smtpd_tls_dh1024_param_file</a>
configuration parameter. </p>
<p> Example: </p>
<pre>
<a href="postconf.5.html#smtpd_tls_dh512_param_file">smtpd_tls_dh512_param_file</a> = /etc/postfix/dh_512.pem
</pre>
<p>This feature is available with Postfix version 2.2.</p>
</DD>
<DT><b><a name="smtpd_tls_dkey_file">smtpd_tls_dkey_file</a>
(default: $<a href="postconf.5.html#smtpd_tls_dcert_file">smtpd_tls_dcert_file</a>)</b></DT><DD>
<p> File with the Postfix SMTP server DSA private key in PEM format.
This file may be combined with the Postfix SMTP server DSA certificate
file specified with $<a href="postconf.5.html#smtpd_tls_dcert_file">smtpd_tls_dcert_file</a>. </p>
<p> The private key must be accessible without a pass-phrase, i.e. it
must not be encrypted. File permissions should grant read-only
access to the system superuser account ("root"), and no access
to anyone else. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtpd_tls_eccert_file">smtpd_tls_eccert_file</a>
(default: empty)</b></DT><DD>
<p> File with the Postfix SMTP server ECDSA certificate in PEM format.
This file may also contain the Postfix SMTP server private ECDSA key. </p>
<p> See the discussion under <a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a> for more details. </p>
<p> Example: </p>
<pre>
<a href="postconf.5.html#smtpd_tls_eccert_file">smtpd_tls_eccert_file</a> = /etc/postfix/ecdsa-scert.pem
</pre>
<p> This feature is available in Postfix 2.6 and later, when Postfix is
compiled and linked with OpenSSL 1.0.0 or later. </p>
</DD>
<DT><b><a name="smtpd_tls_eckey_file">smtpd_tls_eckey_file</a>
(default: $<a href="postconf.5.html#smtpd_tls_eccert_file">smtpd_tls_eccert_file</a>)</b></DT><DD>
<p> File with the Postfix SMTP server ECDSA private key in PEM format.
This file may be combined with the Postfix SMTP server ECDSA certificate
file specified with $<a href="postconf.5.html#smtpd_tls_eccert_file">smtpd_tls_eccert_file</a>. </p>
<p> The private key must be accessible without a pass-phrase, i.e. it
must not be encrypted. File permissions should grant read-only
access to the system superuser account ("root"), and no access
to anyone else. </p>
<p> This feature is available in Postfix 2.6 and later, when Postfix is
compiled and linked with OpenSSL 1.0.0 or later. </p>
</DD>
<DT><b><a name="smtpd_tls_eecdh_grade">smtpd_tls_eecdh_grade</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> The Postfix SMTP server security grade for ephemeral elliptic-curve
Diffie-Hellman (EECDH) key exchange. </p>
<p> The available choices are: </p>
<dl>
<dt><b>none</b></dt> <dd> Don't use EECDH. Ciphers based on EECDH key
exchange will be disabled. This is the default in Postfix versions
2.6 and 2.7. </dd>
<dt><b>strong</b></dt> <dd> Use EECDH with approximately 128
bits of security at a reasonable computational cost. This is the
current best-practice trade-off between security and computational
efficiency. This is the default in Postfix version 2.8 and later.
</dd>
<dt><b>ultra</b></dt> <dd> Use EECDH with approximately 192 bits of
security at computational cost that is approximately twice as high
as 128 bit strength ECC. Barring significant progress in attacks on
elliptic curve crypto-systems, the "strong" curve is sufficient for most
users. </dd>
<dt><b>auto</b></dt> <dd> Use the most preferred curve that is
supported by both the client and the server. This setting requires
Postfix ≥ 3.2 compiled and linked with OpenSSL ≥ 1.0.2. This
is the default setting under the above conditions. </dd>
</dl>
<p> If you want to take maximal advantage of ciphers that offer <a
href="FORWARD_SECRECY_README.html#dfn_fs">forward secrecy</a> see
the <a href="FORWARD_SECRECY_README.html#quick-start">Getting
started</a> section of <a
href="FORWARD_SECRECY_README.html">FORWARD_SECRECY_README</a>. The
full document conveniently presents all information about Postfix
"perfect" forward secrecy support in one place: what forward secrecy
is, how to tweak settings, and what you can expect to see when
Postfix uses ciphers with forward secrecy. </p>
<p> This feature is available in Postfix 2.6 and later, when it is
compiled and linked with OpenSSL 1.0.0 or later on platforms
where EC algorithms have not been disabled by the vendor. </p>
</DD>
<DT><b><a name="smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a>
(default: empty)</b></DT><DD>
<p> List of ciphers or cipher types to exclude from the SMTP server
cipher list at all TLS security levels. Excluding valid ciphers
can create interoperability problems. DO NOT exclude ciphers unless it
is essential to do so. This is not an OpenSSL cipherlist; it is a simple
list separated by whitespace and/or commas. The elements are a single
cipher, or one or more "+" separated cipher properties, in which case
only ciphers matching <b>all</b> the properties are excluded. </p>
<p> Examples (some of these will cause problems): </p>
<blockquote>
<pre>
<a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> = aNULL
<a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> = MD5, DES
<a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> = DES+MD5
<a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> = AES256-SHA, DES-CBC3-MD5
<a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> = kEDH+aRSA
</pre>
</blockquote>
<p> The first setting disables anonymous ciphers. The next setting
disables ciphers that use the MD5 digest algorithm or the (single) DES
encryption algorithm. The next setting disables ciphers that use MD5 and
DES together. The next setting disables the two ciphers "AES256-SHA"
and "DES-CBC3-MD5". The last setting disables ciphers that use "EDH"
key exchange with RSA authentication. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a>
(default: md5)</b></DT><DD>
<p> The message digest algorithm to construct remote SMTP
client-certificate
fingerprints or public key fingerprints (Postfix 2.9 and later)
for <b><a href="postconf.5.html#check_ccert_access">check_ccert_access</a></b> and <b><a href="postconf.5.html#permit_tls_clientcerts">permit_tls_clientcerts</a></b>. The
default algorithm is <b>md5</b>, for backwards compatibility with Postfix
releases prior to 2.5. </p>
<p> Advances in hash
function cryptanalysis have led to md5 being deprecated in favor of sha1.
However, as long as there are no known "second pre-image" attacks
against md5, its use in this context can still be considered safe.
</p>
<p> While additional digest algorithms are often available with OpenSSL's
libcrypto, only those used by libssl in SSL cipher suites are available to
Postfix. </p>
<p> To find the fingerprint of a specific certificate file, with a
specific digest algorithm, run: </p>
<blockquote>
<pre>
$ openssl x509 -noout -fingerprint -<i>digest</i> -in <i>certfile</i>.pem
</pre>
</blockquote>
<p> The text to the right of "=" sign is the desired fingerprint.
For example: </p>
<blockquote>
<pre>
$ openssl x509 -noout -fingerprint -sha1 -in cert.pem
SHA1 Fingerprint=D4:6A:AB:19:24:79:F8:32:BB:A6:CB:66:82:C0:8E:9B:EE:29:A8:1A
</pre>
</blockquote>
<p> To extract the public key fingerprint from an X.509 certificate,
you need to extract the public key from the certificate and compute
the appropriate digest of its DER (ASN.1) encoding. With OpenSSL
the "-pubkey" option of the "x509" command extracts the public
key always in "PEM" format. We pipe the result to another OpenSSL
command that converts the key to DER and then to the "dgst" command
to compute the fingerprint. </p>
<p> The actual command to transform the key to DER format depends
on the version of OpenSSL used. With OpenSSL 1.0.0 and later, the
"pkey" command supports all key types. With OpenSSL 0.9.8 and
earlier, the key type is always RSA (nobody uses DSA, and EC
keys are not fully supported by 0.9.8), so the "rsa" command is
used. </p>
<blockquote>
<pre>
# OpenSSL 1.0 with all certificates and SHA-1 fingerprints.
$ openssl x509 -in cert.pem -noout -pubkey |
openssl pkey -pubin -outform DER |
openssl dgst -sha1 -c
(stdin)= 64:3f:1f:f6:e5:1e:d4:2a:56:8b:fc:09:1a:61:98:b5:bc:7c:60:58
</pre>
</blockquote>
<blockquote>
<pre>
# OpenSSL 0.9.8 with RSA certificates and MD5 fingerprints.
$ openssl x509 -in cert.pem -noout -pubkey |
openssl rsa -pubin -outform DER |
openssl dgst -md5 -c
(stdin)= f4:62:60:f6:12:8f:d5:8d:28:4d:13:a7:db:b2:ff:50
</pre>
</blockquote>
<p> The Postfix SMTP server and client log the peer (leaf) certificate
fingerprint and public key fingerprint when the TLS loglevel is 2 or
higher. </p>
<p> <b>Note:</b> Postfix 2.9.0–2.9.5 computed the public key
fingerprint incorrectly. To use public-key fingerprints, upgrade
to Postfix 2.9.6 or later. </p>
<p> Example: client-certificate access table, with sha1 fingerprints: </p>
<blockquote>
<pre>
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
<a href="postconf.5.html#smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a> = sha1
<a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> =
<a href="postconf.5.html#check_ccert_access">check_ccert_access</a> <a href="DATABASE_README.html#types">hash</a>:/etc/postfix/access,
reject
</pre>
<pre>
/etc/postfix/access:
# Action folded to next line...
AF:88:7C:AD:51:95:6F:36:96:F6:01:FB:2E:48:CD:AB:49:25:A2:3B
OK
85:16:78:FD:73:6E:CE:70:E0:31:5F:0D:3C:C8:6D:C4:2C:24:59:E1
<a href="postconf.5.html#permit_auth_destination">permit_auth_destination</a>
</pre>
</blockquote>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="smtpd_tls_key_file">smtpd_tls_key_file</a>
(default: $<a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a>)</b></DT><DD>
<p> File with the Postfix SMTP server RSA private key in PEM format.
This file may be combined with the Postfix SMTP server RSA certificate
file specified with $<a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a>. </p>
<p> The private key must be accessible without a pass-phrase, i.e. it
must not be encrypted. File permissions should grant read-only
access to the system superuser account ("root"), and no access
to anyone else. </p>
</DD>
<DT><b><a name="smtpd_tls_loglevel">smtpd_tls_loglevel</a>
(default: 0)</b></DT><DD>
<p> Enable additional Postfix SMTP server logging of TLS activity.
Each logging level also includes the information that is logged at
a lower logging level. </p>
<dl compact>
<dt> </dt> <dd> 0 Disable logging of TLS activity. </dd>
<dt> </dt> <dd> 1 Log only a summary message on TLS handshake completion
— no logging of client certificate trust-chain verification errors
if client certificate verification is not required. With Postfix 2.8 and
earlier, log the summary message, peer certificate summary information
and unconditionally log trust-chain verification errors. </dd>
<dt> </dt> <dd> 2 Also log levels during TLS negotiation. </dd>
<dt> </dt> <dd> 3 Also log hexadecimal and ASCII dump of TLS negotiation
process. </dd>
<dt> </dt> <dd> 4 Also log hexadecimal and ASCII dump of complete
transmission after STARTTLS. </dd>
</dl>
<p> Do not use "<a href="postconf.5.html#smtpd_tls_loglevel">smtpd_tls_loglevel</a> = 2" or higher except in case
of problems. Use of loglevel 4 is strongly discouraged. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>
(default: medium)</b></DT><DD>
<p> The minimum TLS cipher grade that the Postfix SMTP server will
use with mandatory TLS encryption. The default grade ("medium") is
sufficiently strong that any benefit from globally restricting TLS
sessions to a more stringent grade is likely negligible, especially
given the fact that many implementations still do not offer any stronger
("high" grade) ciphers, while those that do, will always use "high"
grade ciphers. So insisting on "high" grade ciphers is generally
counter-productive. Allowing "export" or "low" ciphers is typically
not a good idea, as systems limited to just these are limited to
obsolete browsers. No known SMTP clients fail to support at least
one "medium" or "high" grade cipher. </p>
<p> The following cipher grades are supported: </p>
<dl>
<dt><b>export</b></dt>
<dd> Enable "EXPORT" grade or stronger OpenSSL ciphers. The
underlying cipherlist is specified via the <a href="postconf.5.html#tls_export_cipherlist">tls_export_cipherlist</a>
configuration parameter, which you are strongly encouraged to not
change. This choice is insecure and SHOULD NOT be used. </dd>
<dt><b>low</b></dt>
<dd> Enable "LOW" grade or stronger OpenSSL ciphers. The underlying
cipherlist is specified via the <a href="postconf.5.html#tls_low_cipherlist">tls_low_cipherlist</a> configuration
parameter, which you are strongly encouraged to not change. This
choice is insecure and SHOULD NOT be used. </dd>
<dt><b>medium</b></dt>
<dd> Enable "MEDIUM" grade or stronger OpenSSL ciphers. These use 128-bit
or longer symmetric bulk-encryption keys. This is the default minimum
strength for mandatory TLS encryption. The underlying cipherlist is
specified via the <a href="postconf.5.html#tls_medium_cipherlist">tls_medium_cipherlist</a> configuration parameter, which
you are strongly encouraged to not change. </dd>
<dt><b>high</b></dt>
<dd> Enable only "HIGH" grade OpenSSL ciphers. The
underlying cipherlist is specified via the <a href="postconf.5.html#tls_high_cipherlist">tls_high_cipherlist</a>
configuration parameter, which you are strongly encouraged to
not change. </dd>
<dt><b>null</b></dt>
<dd> Enable only the "NULL" OpenSSL ciphers, these provide authentication
without encryption. This setting is only appropriate in the rare
case that all clients are prepared to use NULL ciphers (not normally
enabled in TLS clients). The underlying cipherlist is specified via the
<a href="postconf.5.html#tls_null_cipherlist">tls_null_cipherlist</a> configuration parameter, which you are strongly
encouraged to not change. </dd>
</dl>
<p> Cipher types listed in
<a href="postconf.5.html#smtpd_tls_mandatory_exclude_ciphers">smtpd_tls_mandatory_exclude_ciphers</a> or <a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> are
excluded from the base definition of the selected cipher grade. See
<a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a> for cipher controls that apply to opportunistic
TLS. </p>
<p> The underlying cipherlists for grades other than "null" include
anonymous ciphers, but these are automatically filtered out if the
server is configured to ask for remote SMTP client certificates. You are very
unlikely to need to take any steps to exclude anonymous ciphers, they
are excluded automatically as required. If you must exclude anonymous
ciphers even when Postfix does not need or use peer certificates, set
"<a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> = aNULL". To exclude anonymous ciphers only
when TLS is enforced, set "<a href="postconf.5.html#smtpd_tls_mandatory_exclude_ciphers">smtpd_tls_mandatory_exclude_ciphers</a> = aNULL". </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="smtpd_tls_mandatory_exclude_ciphers">smtpd_tls_mandatory_exclude_ciphers</a>
(default: empty)</b></DT><DD>
<p> Additional list of ciphers or cipher types to exclude from the
Postfix SMTP server cipher list at mandatory TLS security levels.
This list
works in addition to the exclusions listed with <a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a>
(see there for syntax details). </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a>
(default: !SSLv2, !SSLv3)</b></DT><DD>
<p> The SSL/TLS protocols accepted by the Postfix SMTP server with
mandatory TLS encryption. If the list is empty, the server supports
all available SSL/TLS protocol versions. A non-empty value is a
list of protocol names separated by whitespace, commas or colons.
The supported protocol names are "SSLv2", "SSLv3" and "TLSv1", and
are not case sensitive. The default value is "!SSLv2, !SSLv3" for
Postfix releases after the middle of 2015, "!SSLv2" for older
releases. </p>
<p> With Postfix ≥ 2.5 the parameter syntax was expanded to support
protocol exclusions. One can explicitly exclude "SSLv2" by setting
"<a href="postconf.5.html#smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a> = !SSLv2". To exclude both "SSLv2" and
"SSLv3" set "<a href="postconf.5.html#smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a> = !SSLv2, !SSLv3". Listing
the protocols to include, rather than protocols to exclude, is
supported, but not recommended. The exclusion form more closely
matches the underlying OpenSSL interface semantics. </p>
<p> Note: As of OpenSSL 1.0.1 two new protocols are defined, "TLSv1.1"
and "TLSv1.2". When Postfix ≤ 2.5 is linked against OpenSSL 1.0.1
or later, these, or any other new protocol versions, cannot be
disabled. The latest patch levels of Postfix ≥ 2.6, and all
versions of Postfix ≥ 2.10 can disable support for "TLSv1.1" or
"TLSv1.2". </p>
<p> Example: </p>
<pre>
# Preferred syntax with Postfix ≥ 2.5:
<a href="postconf.5.html#smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a> = !SSLv2, !SSLv3
# Legacy syntax:
<a href="postconf.5.html#smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a> = TLSv1
</pre>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="smtpd_tls_protocols">smtpd_tls_protocols</a>
(default: !SSLv2, !SSLv3)</b></DT><DD>
<p> List of TLS protocols that the Postfix SMTP server will exclude
or include with opportunistic TLS encryption. The default value is
"!SSLv2, !SSLv3" for Postfix releases after the middle of 2015,
empty for older releases allowing all protocols to be
used with opportunistic TLS. A non-empty value is a list of protocol
names separated by whitespace, commas or colons. The supported
protocol names are "SSLv2", "SSLv3" and "TLSv1", and are not case
sensitive. </p>
<p> Note: As of OpenSSL 1.0.1 two new protocols are defined, "TLSv1.1"
and "TLSv1.2". The latest patch levels of Postfix ≥ 2.6, and all
versions of Postfix ≥ 2.10 can disable support for "TLSv1.1" or
"TLSv1.2". </p>
<p> To include a protocol list its name, to exclude it, prefix the name
with a "!" character. To exclude SSLv2 for opportunistic TLS set
"<a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a> = !SSLv2". To exclude both "SSLv2" and "SSLv3" set
"<a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a> = !SSLv2, !SSLv3". Explicitly listing the protocols to
include, rather than protocols to exclude, is supported, but not
recommended. The exclusion form more closely matches the underlying
OpenSSL interface semantics. </p>
<p> Example: </p>
<pre>
<a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a> = !SSLv2, !SSLv3
</pre>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="smtpd_tls_received_header">smtpd_tls_received_header</a>
(default: no)</b></DT><DD>
<p> Request that the Postfix SMTP server produces Received: message
headers that include information about the protocol and cipher used,
as well as the remote SMTP client CommonName and client certificate issuer
CommonName. This is disabled by default, as the information may
be modified in transit through other mail servers. Only information
that was recorded by the final destination can be trusted. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtpd_tls_req_ccert">smtpd_tls_req_ccert</a>
(default: no)</b></DT><DD>
<p> With mandatory TLS encryption, require a trusted remote SMTP client
certificate in order to allow TLS connections to proceed. This
option implies "<a href="postconf.5.html#smtpd_tls_ask_ccert">smtpd_tls_ask_ccert</a> = yes". </p>
<p> When TLS encryption is optional, this setting is ignored with
a warning written to the mail log. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtpd_tls_security_level">smtpd_tls_security_level</a>
(default: empty)</b></DT><DD>
<p> The SMTP TLS security level for the Postfix SMTP server; when
a non-empty value is specified, this overrides the obsolete parameters
<a href="postconf.5.html#smtpd_use_tls">smtpd_use_tls</a> and <a href="postconf.5.html#smtpd_enforce_tls">smtpd_enforce_tls</a>. This parameter is ignored with
"<a href="postconf.5.html#smtpd_tls_wrappermode">smtpd_tls_wrappermode</a> = yes". </p>
<p> Specify one of the following security levels: </p>
<dl>
<dt><b>none</b></dt> <dd> TLS will not be used. </dd>
<dt><b>may</b></dt> <dd> Opportunistic TLS: announce STARTTLS support
to remote SMTP clients, but do not require that clients use TLS encryption.
</dd>
<dt><b>encrypt</b></dt> <dd>Mandatory TLS encryption: announce
STARTTLS support to remote SMTP clients, and require that clients use TLS
encryption. According to <a href="http://tools.ietf.org/html/rfc2487">RFC 2487</a> this MUST NOT be applied in case
of a publicly-referenced SMTP server. Instead, this option should
be used only on dedicated servers. </dd>
</dl>
<p> Note 1: the "fingerprint", "verify" and "secure" levels are not
supported here.
The Postfix SMTP server logs a warning and uses "encrypt" instead.
To verify remote SMTP client certificates, see <a href="TLS_README.html">TLS_README</a> for a discussion
of the <a href="postconf.5.html#smtpd_tls_ask_ccert">smtpd_tls_ask_ccert</a>, <a href="postconf.5.html#smtpd_tls_req_ccert">smtpd_tls_req_ccert</a>, and <a href="postconf.5.html#permit_tls_clientcerts">permit_tls_clientcerts</a>
features. </p>
<p> Note 2: The parameter setting "<a href="postconf.5.html#smtpd_tls_security_level">smtpd_tls_security_level</a> =
encrypt" implies "<a href="postconf.5.html#smtpd_tls_auth_only">smtpd_tls_auth_only</a> = yes".</p>
<p> Note 3: when invoked via "sendmail -bs", Postfix will never
offer STARTTLS due to insufficient privileges to access the server
private key. This is intended behavior.</p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="smtpd_tls_session_cache_database">smtpd_tls_session_cache_database</a>
(default: empty)</b></DT><DD>
<p> Name of the file containing the optional Postfix SMTP server
TLS session cache. Specify a database type that supports enumeration,
such as <b>btree</b> or <b>sdbm</b>; there is no need to support
concurrent access. The file is created if it does not exist. The <a href="smtpd.8.html">smtpd(8)</a>
daemon does not use this parameter directly, rather the cache is
implemented indirectly in the <a href="tlsmgr.8.html">tlsmgr(8)</a> daemon. This means that
per-smtpd-instance <a href="master.5.html">master.cf</a> overrides of this parameter are not
effective. Note, that each of the cache databases supported by <a href="tlsmgr.8.html">tlsmgr(8)</a>
daemon: $<a href="postconf.5.html#smtpd_tls_session_cache_database">smtpd_tls_session_cache_database</a>, $<a href="postconf.5.html#smtp_tls_session_cache_database">smtp_tls_session_cache_database</a>
(and with Postfix 2.3 and later $<a href="postconf.5.html#lmtp_tls_session_cache_database">lmtp_tls_session_cache_database</a>), needs to be
stored separately. It is not at this time possible to store multiple
caches in a single database. </p>
<p> Note: <b>dbm</b> databases are not suitable. TLS
session objects are too large. </p>
<p> As of version 2.5, Postfix no longer uses root privileges when
opening this file. The file should now be stored under the Postfix-owned
<a href="postconf.5.html#data_directory">data_directory</a>. As a migration aid, an attempt to open the file
under a non-Postfix directory is redirected to the Postfix-owned
<a href="postconf.5.html#data_directory">data_directory</a>, and a warning is logged. </p>
<p> As of Postfix 2.11 the preferred mechanism for session resumption
is <a href="http://tools.ietf.org/html/rfc5077">RFC 5077</a> TLS session tickets, which don't require server-side
storage. Consequently, for Postfix ≥ 2.11 this parameter should
generally be left empty. TLS session tickets require an OpenSSL
library (at least version 0.9.8h) that provides full support for
this TLS extension. See also <a href="postconf.5.html#smtpd_tls_session_cache_timeout">smtpd_tls_session_cache_timeout</a>. </p>
<p> Example: </p>
<pre>
<a href="postconf.5.html#smtpd_tls_session_cache_database">smtpd_tls_session_cache_database</a> = <a href="DATABASE_README.html#types">btree</a>:/var/lib/postfix/smtpd_scache
</pre>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtpd_tls_session_cache_timeout">smtpd_tls_session_cache_timeout</a>
(default: 3600s)</b></DT><DD>
<p> The expiration time of Postfix SMTP server TLS session cache
information. A cache cleanup is performed periodically
every $<a href="postconf.5.html#smtpd_tls_session_cache_timeout">smtpd_tls_session_cache_timeout</a> seconds. As with
$<a href="postconf.5.html#smtpd_tls_session_cache_database">smtpd_tls_session_cache_database</a>, this parameter is implemented in the
<a href="tlsmgr.8.html">tlsmgr(8)</a> daemon and therefore per-smtpd-instance <a href="master.5.html">master.cf</a> overrides
are not possible. </p>
<p> As of Postfix 2.11 this setting cannot exceed 100 days. If set
≤ 0, session caching is disabled, not just via the database, but
also via <a href="http://tools.ietf.org/html/rfc5077">RFC 5077</a> TLS session tickets, which don't require server-side
storage. If set to a positive value less than 2 minutes, the minimum
value of 2 minutes is used instead. TLS session tickets require
an OpenSSL library (at least version 0.9.8h) that provides full
support for this TLS extension. </p>
<p> This feature is available in Postfix 2.2 and later, and updated
for TLS session ticket support in Postfix 2.11. </p>
</DD>
<DT><b><a name="smtpd_tls_wrappermode">smtpd_tls_wrappermode</a>
(default: no)</b></DT><DD>
<p> Run the Postfix SMTP server in the non-standard "wrapper" mode,
instead of using the STARTTLS command. </p>
<p> If you want to support this service, enable a special port in
<a href="master.5.html">master.cf</a>, and specify "-o <a href="postconf.5.html#smtpd_tls_wrappermode">smtpd_tls_wrappermode</a>=yes" on the SMTP
server's command line. Port 465 (smtps) was once chosen for this
purpose. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="smtpd_upstream_proxy_protocol">smtpd_upstream_proxy_protocol</a>
(default: empty)</b></DT><DD>
<p> The name of the proxy protocol used by an optional before-smtpd
proxy agent. When a proxy agent is used, this protocol conveys local
and remote address and port information. Specify
"<a href="postconf.5.html#smtpd_upstream_proxy_protocol">smtpd_upstream_proxy_protocol</a> = haproxy" to enable the haproxy
protocol. </p>
<p> NOTE: To use the nginx proxy with <a href="smtpd.8.html">smtpd(8)</a>, enable the XCLIENT
protocol with <a href="postconf.5.html#smtpd_authorized_xclient_hosts">smtpd_authorized_xclient_hosts</a>. This supports SASL
authentication in the proxy agent (Postfix 2.9 and later). <p>
<p> This feature is available in Postfix 2.10 and later. </p>
</DD>
<DT><b><a name="smtpd_upstream_proxy_timeout">smtpd_upstream_proxy_timeout</a>
(default: 5s)</b></DT><DD>
<p> The time limit for the proxy protocol specified with the
<a href="postconf.5.html#smtpd_upstream_proxy_protocol">smtpd_upstream_proxy_protocol</a> parameter. </p>
<p> This feature is available in Postfix 2.10 and later. </p>
</DD>
<DT><b><a name="smtpd_use_tls">smtpd_use_tls</a>
(default: no)</b></DT><DD>
<p> Opportunistic TLS: announce STARTTLS support to remote SMTP clients,
but do not require that clients use TLS encryption. </p>
<p> Note: when invoked via "<b>sendmail -bs</b>", Postfix will never offer
STARTTLS due to insufficient privileges to access the server private
key. This is intended behavior. </p>
<p> This feature is available in Postfix 2.2 and later. With
Postfix 2.3 and later use <a href="postconf.5.html#smtpd_tls_security_level">smtpd_tls_security_level</a> instead. </p>
</DD>
<DT><b><a name="smtputf8_autodetect_classes">smtputf8_autodetect_classes</a>
(default: sendmail, verify)</b></DT><DD>
<p> Detect that a message requires SMTPUTF8 support for the specified
mail origin classes. This is a workaround to avoid chicken-and-egg
problems during the initial SMTPUTF8 roll-out in environments with
pre-existing mail flows that contain UTF8. Those mail flows should
not break because Postfix suddenly refuses to deliver such mail
to down-stream MTAs that don't announce SMTPUTF8 support. </p>
<p> The problem is that Postfix cannot rely solely on the sender's
declaration that a message requires SMTPUTF8 support, because UTF8
may be introduced during local processing (for example, the client
hostname in Postfix's Received: header, adding @$<a href="postconf.5.html#myorigin">myorigin</a> or
.$<a href="postconf.5.html#mydomain">mydomain</a> to an incomplete address, address rewriting, alias
expansion, automatic BCC recipients, local forwarding, and changes
made by header checks or Milter applications). </p>
<p> For now, the default is to enable "SMTPUTF8 required" autodetection
only for Postfix sendmail command-line submissions and address
verification probes. This may change once SMTPUTF8 support achieves
world domination. However, sites that add UTF8 content via local
processing (see above) should autodetect the need for SMTPUTF8
support for all email.</p>
<p> Specify one or more of the following: </p>
<dl compact>
<dt> <b> sendmail </b> </dt> <dd> Submission with the Postfix
<a href="sendmail.1.html">sendmail(1)</a> command. </dd>
<dt> <b> smtpd </b> </dt> <dd> Mail received with the <a href="smtpd.8.html">smtpd(8)</a>
daemon. </dd>
<dt> <b> qmqpd </b> </dt> <dd> Mail received with the <a href="qmqpd.8.html">qmqpd(8)</a>
daemon. </dd>
<dt> <b> forward </b> </dt> <dd> Local forwarding or aliasing. When
a message is received with "SMTPUTF8 required", then the forwarded
(aliased) message always has "SMTPUTF8 required". </dd>
<dt> <b> bounce </b> </dt> <dd> Submission by the <a href="bounce.8.html">bounce(8)</a> daemon.
When a message is received with "SMTPUTF8 required", then the
delivery status notification always has "SMTPUTF8 required". </dd>
<dt> <b> notify </b> </dt> <dd> Postmaster notification from the
<a href="smtp.8.html">smtp(8)</a> or <a href="smtpd.8.html">smtpd(8)</a> daemon. </dd>
<dt> <b> verify </b> </dt> <dd> Address verification probe from the
<a href="verify.8.html">verify(8)</a> daemon. </dd>
<dt> <b> all </b> </dt> <dd> Enable SMTPUTF8 autodetection for all
mail. </dd>
</dl>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="smtputf8_enable">smtputf8_enable</a>
(default: yes)</b></DT><DD>
<p> Enable preliminary SMTPUTF8 support for the protocols described
in <a href="http://tools.ietf.org/html/rfc6531">RFC 6531</a>..6533. This requires that Postfix is built to support
these protocols. </p>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="soft_bounce">soft_bounce</a>
(default: no)</b></DT><DD>
<p>
Safety net to keep mail queued that would otherwise be returned to
the sender. This parameter disables locally-generated bounces,
changes the handling of negative responses from remote servers,
content filters or plugins,
and prevents the Postfix SMTP server from rejecting mail permanently
by changing 5xx reply codes into 4xx. However, <a href="postconf.5.html#soft_bounce">soft_bounce</a> is no
cure for address rewriting mistakes or mail routing mistakes.
</p>
<p>
Note: "<a href="postconf.5.html#soft_bounce">soft_bounce</a> = yes" is in some cases implemented by modifying
server responses. Therefore, the response that Postfix logs may
differ from the response that Postfix actually sends or receives.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#soft_bounce">soft_bounce</a> = yes
</pre>
</DD>
<DT><b><a name="stale_lock_time">stale_lock_time</a>
(default: 500s)</b></DT><DD>
<p>
The time after which a stale exclusive mailbox lockfile is removed.
This is used for delivery to file or mailbox.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="stress">stress</a>
(default: empty)</b></DT><DD>
<p> This feature is documented in the <a href="STRESS_README.html">STRESS_README</a> document. </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="strict_7bit_headers">strict_7bit_headers</a>
(default: no)</b></DT><DD>
<p>
Reject mail with 8-bit text in message headers. This blocks mail
from poorly written applications.
</p>
<p>
This feature should not be enabled on a general purpose mail server,
because it is likely to reject legitimate email.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="strict_8bitmime">strict_8bitmime</a>
(default: no)</b></DT><DD>
<p>
Enable both <a href="postconf.5.html#strict_7bit_headers">strict_7bit_headers</a> and <a href="postconf.5.html#strict_8bitmime_body">strict_8bitmime_body</a>.
</p>
<p>
This feature should not be enabled on a general purpose mail server,
because it is likely to reject legitimate email.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="strict_8bitmime_body">strict_8bitmime_body</a>
(default: no)</b></DT><DD>
<p>
Reject 8-bit message body text without 8-bit MIME content encoding
information. This blocks mail from poorly written applications.
</p>
<p>
Unfortunately, this also rejects majordomo approval requests when
the included request contains valid 8-bit MIME mail, and it rejects
bounces from mailers that do not MIME encapsulate 8-bit content
(for example, bounces from qmail or from old versions of Postfix).
</p>
<p>
This feature should not be enabled on a general purpose mail server,
because it is likely to reject legitimate email.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="strict_mailbox_ownership">strict_mailbox_ownership</a>
(default: yes)</b></DT><DD>
<p> Defer delivery when a mailbox file is not owned by its recipient.
The default setting is not backwards compatible. </p>
<p> This feature is available in Postfix 2.5.3 and later. </p>
</DD>
<DT><b><a name="strict_mime_encoding_domain">strict_mime_encoding_domain</a>
(default: no)</b></DT><DD>
<p>
Reject mail with invalid Content-Transfer-Encoding: information
for the message/* or multipart/* MIME content types. This blocks
mail from poorly written software.
</p>
<p>
This feature should not be enabled on a general purpose mail server,
because it will reject mail after a single violation.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="strict_rfc821_envelopes">strict_rfc821_envelopes</a>
(default: no)</b></DT><DD>
<p>
Require that addresses received in SMTP MAIL FROM and RCPT TO
commands are enclosed with <>, and that those addresses do
not contain <a href="http://tools.ietf.org/html/rfc822">RFC 822</a> style comments or phrases. This stops mail
from poorly written software.
</p>
<p>
By default, the Postfix SMTP server accepts <a href="http://tools.ietf.org/html/rfc822">RFC 822</a> syntax in MAIL
FROM and RCPT TO addresses.
</p>
</DD>
<DT><b><a name="strict_smtputf8">strict_smtputf8</a>
(default: no)</b></DT><DD>
<p> Enable stricter enforcement of the SMTPUTF8 protocol. The Postfix
SMTP server accepts UTF8 sender or recipient addresses only when
the client requests an SMTPUTF8 mail transaction. </p>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="sun_mailtool_compatibility">sun_mailtool_compatibility</a>
(default: no)</b></DT><DD>
<p>
Obsolete SUN mailtool compatibility feature. Instead, use
"<a href="postconf.5.html#mailbox_delivery_lock">mailbox_delivery_lock</a> = dotlock".
</p>
</DD>
<DT><b><a name="swap_bangpath">swap_bangpath</a>
(default: yes)</b></DT><DD>
<p>
Enable the rewriting of "site!user" into "user@site". This is
necessary if your machine is connected to UUCP networks. It is
enabled by default.
</p>
<p> Note: with Postfix version 2.2, message header address rewriting
happens only when one of the following conditions is true: </p>
<ul>
<li> The message is received with the Postfix <a href="sendmail.1.html">sendmail(1)</a> command,
<li> The message is received from a network client that matches
$<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a>,
<li> The message is received from the network, and the
<a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> parameter specifies a non-empty value.
</ul>
<p> To get the behavior before Postfix version 2.2, specify
"<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> = <a href="DATABASE_README.html#types">static</a>:all". </p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#swap_bangpath">swap_bangpath</a> = no
</pre>
</DD>
<DT><b><a name="syslog_facility">syslog_facility</a>
(default: mail)</b></DT><DD>
<p>
The syslog facility of Postfix logging. Specify a facility as
defined in syslog.conf(5). The default facility is "mail".
</p>
<p>
Warning: a non-default <a href="postconf.5.html#syslog_facility">syslog_facility</a> setting takes effect only
after a Postfix process has completed initialization. Errors during
process initialization will be logged with the default facility.
Examples are errors while parsing the command line arguments, and
errors while accessing the Postfix <a href="postconf.5.html">main.cf</a> configuration file.
</p>
</DD>
<DT><b><a name="syslog_name">syslog_name</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
A prefix that is prepended to the process name in syslog
records, so that, for example, "smtpd" becomes "prefix/smtpd".
</p>
<p>
Warning: a non-default <a href="postconf.5.html#syslog_name">syslog_name</a> setting takes effect only after
a Postfix process has completed initialization. Errors during
process initialization will be logged with the default name. Examples
are errors while parsing the command line arguments, and errors
while accessing the Postfix <a href="postconf.5.html">main.cf</a> configuration file.
</p>
</DD>
<DT><b><a name="tcp_windowsize">tcp_windowsize</a>
(default: 0)</b></DT><DD>
<p> An optional workaround for routers that break TCP window scaling.
Specify a value > 0 and < 65536 to enable this feature. With
Postfix TCP servers (<a href="smtpd.8.html">smtpd(8)</a>, <a href="qmqpd.8.html">qmqpd(8)</a>), this feature is implemented
by the Postfix <a href="master.8.html">master(8)</a> daemon. </p>
<p> To change this parameter without stopping Postfix, you need to
first terminate all Postfix TCP servers: </p>
<blockquote>
<pre>
# postconf -e <a href="postconf.5.html#master_service_disable">master_service_disable</a>=inet
# postfix reload
</pre>
</blockquote>
<p> This immediately terminates all processes that accept network
connections. Next, you enable Postfix TCP servers with the updated
<a href="postconf.5.html#tcp_windowsize">tcp_windowsize</a> setting: </p>
<blockquote>
<pre>
# postconf -e <a href="postconf.5.html#tcp_windowsize">tcp_windowsize</a>=65535 <a href="postconf.5.html#master_service_disable">master_service_disable</a>=
# postfix reload
</pre>
</blockquote>
<p> If you skip these steps with a running Postfix system, then the
<a href="postconf.5.html#tcp_windowsize">tcp_windowsize</a> change will work only for Postfix TCP clients (<a href="smtp.8.html">smtp(8)</a>,
<a href="lmtp.8.html">lmtp(8)</a>). </p>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="tls_append_default_CA">tls_append_default_CA</a>
(default: no)</b></DT><DD>
<p> Append the system-supplied default Certification Authority
certificates to the ones specified with *_tls_CApath or *_tls_CAfile.
The default is "no"; this prevents Postfix from trusting third-party
certificates and giving them relay permission with
<a href="postconf.5.html#permit_tls_all_clientcerts">permit_tls_all_clientcerts</a>. </p>
<p> This feature is available in Postfix 2.4.15, 2.5.11, 2.6.8,
2.7.2 and later versions. Specify "<a href="postconf.5.html#tls_append_default_CA">tls_append_default_CA</a> = yes" for
backwards compatibility, to avoid breaking certificate verification
with sites that don't use <a href="postconf.5.html#permit_tls_all_clientcerts">permit_tls_all_clientcerts</a>. </p>
</DD>
<DT><b><a name="tls_daemon_random_bytes">tls_daemon_random_bytes</a>
(default: 32)</b></DT><DD>
<p> The number of pseudo-random bytes that an <a href="smtp.8.html">smtp(8)</a> or <a href="smtpd.8.html">smtpd(8)</a>
process requests from the <a href="tlsmgr.8.html">tlsmgr(8)</a> server in order to seed its
internal pseudo random number generator (PRNG). The default of 32
bytes (equivalent to 256 bits) is sufficient to generate a 128bit
(or 168bit) session key. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="tls_dane_digest_agility">tls_dane_digest_agility</a>
(default: on)</b></DT><DD>
<p> Configure <a href="http://tools.ietf.org/html/rfc7671">RFC7671</a> DANE TLSA digest algorithm agility.
Do not change this setting from its default value. </p>
<p> See Section 8 of <a href="http://tools.ietf.org/html/rfc7671">RFC7671</a> for correct key rotation procedures. </p>
<p> This feature is available in Postfix 2.11 through 3.1. Postfix
3.2 and later ignore this configuration parameter and behave as
though it were set to "on". </p>
</DD>
<DT><b><a name="tls_dane_digests">tls_dane_digests</a>
(default: sha512 sha256)</b></DT><DD>
<p> DANE TLSA (<a href="http://tools.ietf.org/html/rfc6698">RFC 6698</a>, <a href="http://tools.ietf.org/html/rfc7671">RFC 7671</a>, <a href="http://tools.ietf.org/html/rfc7672">RFC 7672</a>) resource-record "matching
type" digest algorithms in descending preference order. All the
specified algorithms must be supported by the underlying OpenSSL
library, otherwise the Postfix SMTP client will not support DANE
TLSA security. </p>
<p> Specify a list of digest names separated by commas and/or
whitespace. Each digest name may be followed by an optional
"=<number>" suffix. For example, "sha512" may instead be specified
as "sha512=2" and "sha256" may instead be specified as "sha256=1".
The optional number must match the <a
href="https://www.iana.org/assignments/dane-parameters/dane-parameters.xhtml#matching-types"
>IANA</a> assigned TLSA matching type number the algorithm in question.
Postfix will check this constraint for the algorithms it knows about.
Additional matching type algorithms registered with IANA can be added
with explicit numbers provided they are supported by OpenSSL. </p>
<p> Invalid list elements are logged with a warning and disable DANE
support. TLSA RRs that specify digests not included in the list are
ignored with a warning. </p>
<p> Note: It is unwise to omit sha256 from the digest list. This
digest algorithm is the only mandatory to implement digest algorithm
in <a href="http://tools.ietf.org/html/rfc6698">RFC 6698</a>, and many servers are expected publish TLSA records
with just sha256 digests. Unless one of the standard digests is
seriously compromised and servers have had ample time to update their
TLSA records you should not omit any standard digests, just arrange
them in order from strongest to weakest. </p>
<p> This feature is available in Postfix 2.11 and later. </p>
</DD>
<DT><b><a name="tls_dane_trust_anchor_digest_enable">tls_dane_trust_anchor_digest_enable</a>
(default: yes)</b></DT><DD>
<p> Enable support for <a href="http://tools.ietf.org/html/rfc6698">RFC 6698</a> (DANE TLSA) DNS records that contain
digests of trust-anchors with certificate usage "2". Do not change
this setting from its default value. </p>
<p> This feature is available in Postfix 2.11 through 3.1. It has
been withdrawn in Postfix 3.2, as trust-anchor TLSA records are now
widely used and have proved sufficiently reliable. Postfix 3.2 and
later ignore this configuration parameter and behaves as though it
were set to "yes". </p>
</DD>
<DT><b><a name="tls_disable_workarounds">tls_disable_workarounds</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> List or bit-mask of OpenSSL bug work-arounds to disable. </p>
<p> The OpenSSL toolkit includes a set of work-arounds for buggy SSL/TLS
implementations. Applications, such as Postfix, that want to maximize
interoperability ask the OpenSSL library to enable the full set of
recommended work-arounds. </p>
<p> From time to time, it is discovered that a work-around creates a
security issue, and should no longer be used. If upgrading OpenSSL
to a fixed version is not an option or an upgrade is not available
in a timely manner, or in closed environments where no buggy clients
or servers exist, it may be appropriate to disable some or all of the
OpenSSL interoperability work-arounds. This parameter specifies which
bug work-arounds to disable. </p>
<p> If the value of the parameter is a hexadecimal long integer starting
with "0x", the bug work-arounds corresponding to the bits specified in
its value are removed from the <b>SSL_OP_ALL</b> work-around bit-mask
(see openssl/ssl.h and SSL_CTX_set_options(3)). You can specify more
bits than are present in SSL_OP_ALL, excess bits are ignored. Specifying
0xFFFFFFFF disables all bug-workarounds on a 32-bit system. This should
also be sufficient on 64-bit systems, until OpenSSL abandons support
for 32-bit systems and starts using the high 32 bits of a 64-bit
bug-workaround mask. </p>
<p> Otherwise, the parameter is a white-space or comma separated list
of specific named bug work-arounds chosen from the list below. It
is possible that your OpenSSL version includes new bug work-arounds
added after your Postfix source code was last updated, in that case
you can only disable one of these via the hexadecimal syntax above. </p>
<dl>
<dt><b>MICROSOFT_SESS_ID_BUG</b></dt> <dd>See SSL_CTX_set_options(3)</dd>
<dt><b>NETSCAPE_CHALLENGE_BUG</b></dt> <dd>See SSL_CTX_set_options(3)</dd>
<dt><b>LEGACY_SERVER_CONNECT</b></dt> <dd>See SSL_CTX_set_options(3)</dd>
<dt><b>NETSCAPE_REUSE_CIPHER_CHANGE_BUG</b></dt> <dd> also aliased
as <b>CVE-2010-4180</b>. Postfix 2.8 disables this work-around by
default with OpenSSL versions that may predate the fix. Fixed in
OpenSSL 0.9.8q and OpenSSL 1.0.0c.</dd>
<dt><b>SSLREF2_REUSE_CERT_TYPE_BUG</b></dt> <dd>See
SSL_CTX_set_options(3)</dd>
<dt><b>MICROSOFT_BIG_SSLV3_BUFFER</b></dt> <dd>See
SSL_CTX_set_options(3)</dd>
<dt><b>MSIE_SSLV2_RSA_PADDING</b></dt> <dd> also aliased as
<b>CVE-2005-2969</b>. Postfix 2.8 disables this work-around by
default with OpenSSL versions that may predate the fix. Fixed in
OpenSSL 0.9.7h and OpenSSL 0.9.8a.</dd>
<dt><b>SSLEAY_080_CLIENT_DH_BUG</b></dt> <dd>See
SSL_CTX_set_options(3)</dd>
<dt><b>TLS_D5_BUG</b></dt> <dd>See SSL_CTX_set_options(3)</dd>
<dt><b>TLS_BLOCK_PADDING_BUG</b></dt> <dd>See SSL_CTX_set_options(3)</dd>
<dt><b>TLS_ROLLBACK_BUG</b></dt> <dd>See SSL_CTX_set_options(3).
This is disabled in OpenSSL 0.9.7 and later. Nobody should still
be using 0.9.6! </dd>
<dt><b>DONT_INSERT_EMPTY_FRAGMENTS</b></dt> <dd>See
SSL_CTX_set_options(3)</dd>
<dt><b>CRYPTOPRO_TLSEXT_BUG</b></dt> <dd>New with GOST support in
OpenSSL 1.0.0.</dd>
</dl>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tls_eecdh_auto_curves">tls_eecdh_auto_curves</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> The prioritized list of elliptic curves supported by the Postfix
SMTP client and server. These curves are used by the Postfix SMTP
server when "<a href="postconf.5.html#smtpd_tls_eecdh_grade">smtpd_tls_eecdh_grade</a> = auto". The selected curves
must be implemented by OpenSSL and be standardized for use in TLS
(<a href="http://tools.ietf.org/html/rfc4492">RFC 4492</a> or its imminent successor). It is unwise to list only
"bleeding-edge" curves supported by a small subset of clients. The
default list is suitable for most users. </p>
<p> Postfix skips curve names that are unknown to OpenSSL, or that
are known but not yet implemented. This makes it possible to
"anticipate" support for curves that should be used once they become
available. In particular, in some OpenSSL versions, the new <a href="http://tools.ietf.org/html/rfc8031">RFC</a>
<a href="http://tools.ietf.org/html/rfc8031">8031</a> curves "X25519" and "X448" may be known by name, but ECDH
support for either or both may be missing. These curves may appear
in the default value of this parameter, even though they'll only
be usable with later versions of OpenSSL. </p>
<p> This feature is available in Postfix 3.2 and later, when it is
compiled and linked with OpenSSL 1.0.2 or later on platforms where
EC algorithms have not been disabled by the vendor. </p>
</DD>
<DT><b><a name="tls_eecdh_strong_curve">tls_eecdh_strong_curve</a>
(default: prime256v1)</b></DT><DD>
<p> The elliptic curve used by the Postfix SMTP server for sensibly
strong
ephemeral ECDH key exchange. This curve is used by the Postfix SMTP
server when "<a href="postconf.5.html#smtpd_tls_eecdh_grade">smtpd_tls_eecdh_grade</a> = strong". The phrase "sensibly
strong" means approximately 128-bit security based on best known
attacks. The selected curve must be implemented by OpenSSL (as
reported by ecparam(1) with the "-list_curves" option) and be one
of the curves listed in Section 5.1.1 of <a href="http://tools.ietf.org/html/rfc4492">RFC 4492</a>. You should not
generally change this setting. Remote SMTP client implementations
must support this curve for EECDH key exchange to take place. It
is unwise to choose an "bleeding-edge" curve supported by only a
small subset of clients. </p>
<p> The default "strong" curve is rated in NSA <a
href="http://www.nsa.gov/ia/programs/suiteb_cryptography/">Suite
B</a> for information classified up to SECRET. </p>
<p> Note: elliptic curve names are poorly standardized; different
standards groups are assigning different names to the same underlying
curves. The curve with the X9.62 name "prime256v1" is also known
under the SECG name "secp256r1", but OpenSSL does not recognize the
latter name. </p>
<p> If you want to take maximal advantage of ciphers that offer <a
href="FORWARD_SECRECY_README.html#dfn_fs">forward secrecy</a> see
the <a href="FORWARD_SECRECY_README.html#quick-start">Getting
started</a> section of <a
href="FORWARD_SECRECY_README.html">FORWARD_SECRECY_README</a>. The
full document conveniently presents all information about Postfix
"perfect" forward secrecy support in one place: what forward secrecy
is, how to tweak settings, and what you can expect to see when
Postfix uses ciphers with forward secrecy. </p>
<p> This feature is available in Postfix 2.6 and later, when it is
compiled and linked with OpenSSL 1.0.0 or later on platforms where
EC algorithms have not been disabled by the vendor. </p>
</DD>
<DT><b><a name="tls_eecdh_ultra_curve">tls_eecdh_ultra_curve</a>
(default: secp384r1)</b></DT><DD>
<p> The elliptic curve used by the Postfix SMTP server for maximally
strong
ephemeral ECDH key exchange. This curve is used by the Postfix SMTP
server when "<a href="postconf.5.html#smtpd_tls_eecdh_grade">smtpd_tls_eecdh_grade</a> = ultra". The phrase "maximally
strong" means approximately 192-bit security based on best known attacks.
This additional strength comes at a significant computational cost, most
users should instead set "<a href="postconf.5.html#smtpd_tls_eecdh_grade">smtpd_tls_eecdh_grade</a> = strong". The selected
curve must be implemented by OpenSSL (as reported by ecparam(1) with the
"-list_curves" option) and be one of the curves listed in Section 5.1.1
of <a href="http://tools.ietf.org/html/rfc4492">RFC 4492</a>. You should not generally change this setting. </p>
<p> This default "ultra" curve is rated in NSA <a
href="http://www.nsa.gov/ia/programs/suiteb_cryptography/">Suite
B</a> for information classified up to TOP SECRET. </p>
<p> If you want to take maximal advantage of ciphers that offer <a
href="FORWARD_SECRECY_README.html#dfn_fs">forward secrecy</a> see
the <a href="FORWARD_SECRECY_README.html#quick-start">Getting
started</a> section of <a
href="FORWARD_SECRECY_README.html">FORWARD_SECRECY_README</a>. The
full document conveniently presents all information about Postfix
"perfect" forward secrecy support in one place: what forward secrecy
is, how to tweak settings, and what you can expect to see when
Postfix uses ciphers with forward secrecy. </p>
<p> This feature is available in Postfix 2.6 and later, when it is
compiled and linked with OpenSSL 1.0.0 or later on platforms where
EC algorithms have not been disabled by the vendor. </p>
</DD>
<DT><b><a name="tls_export_cipherlist">tls_export_cipherlist</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> The OpenSSL cipherlist for "export" or higher grade ciphers. This
defines the meaning of the "export" setting in <a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a>,
<a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>, <a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a>, <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a>,
<a href="postconf.5.html#lmtp_tls_ciphers">lmtp_tls_ciphers</a>, and <a href="postconf.5.html#lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a>. With Postfix
releases before the middle of 2015 this is the default cipherlist
for the opportunistic ("may") TLS client security level and also
the default cipherlist for the SMTP server. You are strongly
encouraged to not change this setting. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="tls_high_cipherlist">tls_high_cipherlist</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> The OpenSSL cipherlist for "high" grade ciphers. This defines
the meaning of the "high" setting in <a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a>,
<a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>, <a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a>, <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a>,
<a href="postconf.5.html#lmtp_tls_ciphers">lmtp_tls_ciphers</a>, and <a href="postconf.5.html#lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a>. You are strongly
encouraged to not change this setting. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="tls_legacy_public_key_fingerprints">tls_legacy_public_key_fingerprints</a>
(default: no)</b></DT><DD>
<p> A temporary migration aid for sites that use certificate
<i>public-key</i> fingerprints with Postfix 2.9.0..2.9.5, which use
an incorrect algorithm. This parameter has no effect on the certificate
fingerprint support that is available since Postfix 2.2. </p>
<p> Specify "<a href="postconf.5.html#tls_legacy_public_key_fingerprint">tls_legacy_public_key_fingerprints</a> = yes" temporarily,
pending a migration from configuration files with incorrect Postfix
2.9.0..2.9.5 certificate public-key finger prints, to the correct
fingerprints used by Postfix 2.9.6 and later. To compute the correct
certificate public-key fingerprints, see <a href="TLS_README.html">TLS_README</a>. </p>
<p> This feature is available in Postfix 2.9.6 and later. </p>
</DD>
<DT><b><a name="tls_low_cipherlist">tls_low_cipherlist</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> The OpenSSL cipherlist for "low" or higher grade ciphers. This defines
the meaning of the "low" setting in <a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a>,
<a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>, <a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a>, <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a>,
<a href="postconf.5.html#lmtp_tls_ciphers">lmtp_tls_ciphers</a>, and <a href="postconf.5.html#lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a>. You are strongly
encouraged to not change this setting. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="tls_medium_cipherlist">tls_medium_cipherlist</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> The OpenSSL cipherlist for "medium" or higher grade ciphers. This
defines the meaning of the "medium" setting in <a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a>,
<a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>, <a href="postconf.5.html#smtp_tls_ciphers">smtp_tls_ciphers</a>, <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a>,
<a href="postconf.5.html#lmtp_tls_ciphers">lmtp_tls_ciphers</a>, and <a href="postconf.5.html#lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a>. This is the
default cipherlist for mandatory TLS encryption in the TLS client
(with anonymous ciphers disabled when verifying server certificates).
This is the default cipherlist for opportunistic TLS with Postfix
releases after the middle of 2015. You are strongly encouraged to
not change this setting. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="tls_null_cipherlist">tls_null_cipherlist</a>
(default: eNULL:!aNULL)</b></DT><DD>
<p> The OpenSSL cipherlist for "NULL" grade ciphers that provide
authentication without encryption. This defines the meaning of the "null"
setting in smtpd_mandatory_tls_ciphers, <a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> and
<a href="postconf.5.html#lmtp_tls_mandatory_ciphers">lmtp_tls_mandatory_ciphers</a>. You are strongly encouraged to not
change this setting. </p>
<p> This feature is available in Postfix 2.3 and later. </p>
</DD>
<DT><b><a name="tls_preempt_cipherlist">tls_preempt_cipherlist</a>
(default: no)</b></DT><DD>
<p> With SSLv3 and later, use the Postfix SMTP server's cipher
preference order instead of the remote client's cipher preference
order. </p>
<p> By default, the OpenSSL server selects the client's most preferred
cipher that the server supports. With SSLv3 and later, the server may
choose its own most preferred cipher that is supported (offered) by
the client. Setting "<a href="postconf.5.html#tls_preempt_cipherlist">tls_preempt_cipherlist</a> = yes" enables server cipher
preferences. </p>
<p> While server cipher selection may in some cases lead to a more secure
or performant cipher choice, there is some risk of interoperability
issues. In the past, some SSL clients have listed lower priority ciphers
that they did not implement correctly. If the server chooses a cipher
that the client prefers less, it may select a cipher whose client
implementation is flawed. Most notably Windows 2003 Microsoft
Exchange servers have flawed implementations of DES-CBC3-SHA, which
OpenSSL considers stronger than RC4-SHA. Enabling server cipher-suite
selection may create interoperability issues with Windows 2003
Microsoft Exchange clients. </p>
<p> This feature is available in Postfix 2.8 and later, in combination
with OpenSSL 0.9.7 and later. </p>
</DD>
<DT><b><a name="tls_random_bytes">tls_random_bytes</a>
(default: 32)</b></DT><DD>
<p> The number of bytes that <a href="tlsmgr.8.html">tlsmgr(8)</a> reads from $<a href="postconf.5.html#tls_random_source">tls_random_source</a>
when (re)seeding the in-memory pseudo random number generator (PRNG)
pool. The default of 32 bytes (256 bits) is good enough for 128bit
symmetric keys. If using EGD or a device file, a maximum of 255
bytes is read. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="tls_random_exchange_name">tls_random_exchange_name</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> Name of the pseudo random number generator (PRNG) state file
that is maintained by <a href="tlsmgr.8.html">tlsmgr(8)</a>. The file is created when it does
not exist, and its length is fixed at 1024 bytes. </p>
<p> As of version 2.5, Postfix no longer uses root privileges when
opening this file, and the default file location was changed from
${<a href="postconf.5.html#config_directory">config_directory</a>}/prng_exch to ${<a href="postconf.5.html#data_directory">data_directory</a>}/prng_exch. As
a migration aid, an attempt to open the file under a non-Postfix
directory is redirected to the Postfix-owned <a href="postconf.5.html#data_directory">data_directory</a>, and a
warning is logged. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="tls_random_prng_update_period">tls_random_prng_update_period</a>
(default: 3600s)</b></DT><DD>
<p> The time between attempts by <a href="tlsmgr.8.html">tlsmgr(8)</a> to save the state of
the pseudo random number generator (PRNG) to the file specified
with $<a href="postconf.5.html#tls_random_exchange_name">tls_random_exchange_name</a>. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="tls_random_reseed_period">tls_random_reseed_period</a>
(default: 3600s)</b></DT><DD>
<p> The maximal time between attempts by <a href="tlsmgr.8.html">tlsmgr(8)</a> to re-seed the
in-memory pseudo random number generator (PRNG) pool from external
sources. The actual time between re-seeding attempts is calculated
using the PRNG, and is between 0 and the time specified. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="tls_random_source">tls_random_source</a>
(default: see "postconf -d" output)</b></DT><DD>
<p> The external entropy source for the in-memory <a href="tlsmgr.8.html">tlsmgr(8)</a> pseudo
random number generator (PRNG) pool. Be sure to specify a non-blocking
source. If this source is not a regular file, the entropy source
type must be prepended: egd:/path/to/egd_socket for a source with
EGD compatible socket interface, or dev:/path/to/device for a
device file. </p>
<p> Note: on OpenBSD systems specify /dev/arandom when /dev/urandom
gives timeout errors. </p>
<p> This feature is available in Postfix 2.2 and later. </p>
</DD>
<DT><b><a name="tls_session_ticket_cipher">tls_session_ticket_cipher</a>
(default: Postfix ≥ 3.0: aes-256-cbc, Postfix < 3.0: aes-128-cbc)</b></DT><DD>
<p> Algorithm used to encrypt <a href="http://tools.ietf.org/html/rfc5077">RFC5077</a> TLS session tickets. This
algorithm must use CBC mode, have a 128-bit block size, and must
have a key length between 128 and 256 bits. The default is
aes-256-cbc. Overriding the default to choose a different algorithm
is discouraged. </p>
<p> Setting this parameter empty disables session ticket support
in the Postfix SMTP server. Another way to disable session ticket
support is via the <a href="postconf.5.html#tls_ssl_options">tls_ssl_options</a> parameter. </p>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="tls_ssl_options">tls_ssl_options</a>
(default: empty)</b></DT><DD>
<p> List or bit-mask of OpenSSL options to enable. </p>
<p> The OpenSSL toolkit provides a set of options that applications
can enable to tune the OpenSSL behavior. Some of these work around
bugs in other implementations and are on by default. You can use
the <a href="postconf.5.html#tls_disable_workarounds">tls_disable_workarounds</a> parameter to selectively disable some
or all of the bug work-arounds, making OpenSSL more strict at the
cost of non-interoperability with SSL clients or servers that exhibit
the bugs. </p>
<p> Other options are off by default, and typically enable or disable
features rather than bug work-arounds. These may be turned on (with
care) via the <a href="postconf.5.html#tls_ssl_options">tls_ssl_options</a> parameter. The value is a white-space
or comma separated list of named options chosen from the list below.
The names are not case-sensitive, you can use lower-case if you
prefer. The upper case values below match the corresponding macro
name in the ssl.h header file with the SSL_OP_ prefix removed. It
is possible that your OpenSSL version includes new options added
after your Postfix source code was last updated, in that case you
can only enable one of these via the hexadecimal syntax below. </p>
<p> You should only enable features via the hexadecimal mask when
the need to control the feature is critical (to deal with a new
vulnerability or a serious interoperability problem). Postfix DOES
NOT promise backwards compatible behavior with respect to the mask
bits. A feature enabled via the mask in one release may be enabled
by other means in a later release, and the mask bit will then be
ignored. Therefore, use of the hexadecimal mask is only a temporary
measure until a new Postfix or OpenSSL release provides a better
solution. </p>
<p> If the value of the parameter is a hexadecimal long integer
starting with "0x", the options corresponding to the bits specified
in its value are enabled (see openssl/ssl.h and SSL_CTX_set_options(3)).
You can only enable options not already controlled by other Postfix
settings. For example, you cannot disable protocols or enable
server cipher preference. Do not attempt to turn all features by
specifying 0xFFFFFFFF, this is unlikely to be a good idea. </p>
<dl>
<dt><b>LEGACY_SERVER_CONNECT</b></dt> <dd>See SSL_CTX_set_options(3).</dd>
<dt><b>NO_TICKET</b></dt> <dd>See SSL_CTX_set_options(3).</dd>
<dt><b>NO_COMPRESSION</b></dt> <dd>Disable SSL compression even if
supported by the OpenSSL library. Compression is CPU-intensive,
and compression before encryption does not always improve security. </dd>
</dl>
<p> This feature is available in Postfix 2.11 and later. </p>
</DD>
<DT><b><a name="tls_wildcard_matches_multiple_labels">tls_wildcard_matches_multiple_labels</a>
(default: yes)</b></DT><DD>
<p> Match multiple DNS labels with "*" in wildcard certificates.
</p>
<p> Some mail service providers prepend the customer domain name
to a base domain for which they have a wildcard TLS certificate.
For example, the MX records for example.com hosted by example.net
may be: </p>
<blockquote>
<pre>
example.com. IN MX 0 example.com.mx1.example.net.
example.com. IN MX 0 example.com.mx2.example.net.
</pre>
</blockquote>
<p> and the TLS certificate may be for "*.example.net". The "*"
then corresponds with multiple labels in the mail server domain
name. While multi-label wildcards are not widely supported, and
are not blessed by any standard, there is little to be gained by
disallowing their use in this context. </p>
<p> Notes: <p>
<ul>
<li> <p> In a certificate name, the "*" is special only when it is
used as the first label. </p>
<li> <p> While Postfix (2.11 or later) can match "*" with multiple
domain name labels, other implementations likely will not. </p>
<li> <p> Earlier Postfix implementations behave as if
"<a href="postconf.5.html#tls_wildcard_matches_multiple_labels">tls_wildcard_matches_multiple_labels</a> = no". </p>
</ul>
<p> This feature is available in Postfix 2.11 and later. </p>
</DD>
<DT><b><a name="tlsmgr_service_name">tlsmgr_service_name</a>
(default: tlsmgr)</b></DT><DD>
<p> The name of the <a href="tlsmgr.8.html">tlsmgr(8)</a> service entry in <a href="master.5.html">master.cf</a>. This
service maintains TLS session caches and other information in support
of TLS. </p>
<p> This feature is available in Postfix 2.11 and later. </p>
</DD>
<DT><b><a name="tlsproxy_enforce_tls">tlsproxy_enforce_tls</a>
(default: $<a href="postconf.5.html#smtpd_enforce_tls">smtpd_enforce_tls</a>)</b></DT><DD>
<p> Mandatory TLS: announce STARTTLS support to remote SMTP clients, and
require that clients use TLS encryption. See <a href="postconf.5.html#smtpd_enforce_tls">smtpd_enforce_tls</a> for
further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_service_name">tlsproxy_service_name</a>
(default: tlsproxy)</b></DT><DD>
<p> The name of the <a href="tlsproxy.8.html">tlsproxy(8)</a> service entry in <a href="master.5.html">master.cf</a>. This
service performs plaintext <=> TLS ciphertext conversion. <p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_CAfile">tlsproxy_tls_CAfile</a>
(default: $<a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a>)</b></DT><DD>
<p> A file containing (PEM format) CA certificates of root CAs
trusted to sign either remote SMTP client certificates or intermediate
CA certificates. See <a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a> for further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_CApath">tlsproxy_tls_CApath</a>
(default: $<a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a>)</b></DT><DD>
<p> A directory containing (PEM format) CA certificates of root CAs
trusted to sign either remote SMTP client certificates or intermediate
CA certificates. See <a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a> for further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_always_issue_session_ids">tlsproxy_tls_always_issue_session_ids</a>
(default: $<a href="postconf.5.html#smtpd_tls_always_issue_session_ids">smtpd_tls_always_issue_session_ids</a>)</b></DT><DD>
<p> Force the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server to issue a TLS session id,
even when TLS session caching is turned off. See
<a href="postconf.5.html#smtpd_tls_always_issue_session_ids">smtpd_tls_always_issue_session_ids</a> for further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_ask_ccert">tlsproxy_tls_ask_ccert</a>
(default: $<a href="postconf.5.html#smtpd_tls_ask_ccert">smtpd_tls_ask_ccert</a>)</b></DT><DD>
<p> Ask a remote SMTP client for a client certificate. See
<a href="postconf.5.html#smtpd_tls_ask_ccert">smtpd_tls_ask_ccert</a> for further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_ccert_verifydepth">tlsproxy_tls_ccert_verifydepth</a>
(default: $<a href="postconf.5.html#smtpd_tls_ccert_verifydepth">smtpd_tls_ccert_verifydepth</a>)</b></DT><DD>
<p> The verification depth for remote SMTP client certificates. A
depth of 1 is sufficient if the issuing CA is listed in a local CA
file. See <a href="postconf.5.html#smtpd_tls_ccert_verifydepth">smtpd_tls_ccert_verifydepth</a> for further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_cert_file">tlsproxy_tls_cert_file</a>
(default: $<a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a>)</b></DT><DD>
<p> File with the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server RSA certificate in PEM
format. This file may also contain the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server
private RSA key. See <a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a> for further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_ciphers">tlsproxy_tls_ciphers</a>
(default: $<a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a>)</b></DT><DD>
<p> The minimum TLS cipher grade that the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server
will use with opportunistic TLS encryption. See <a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a>
for further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_dcert_file">tlsproxy_tls_dcert_file</a>
(default: $<a href="postconf.5.html#smtpd_tls_dcert_file">smtpd_tls_dcert_file</a>)</b></DT><DD>
<p> File with the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server DSA certificate in PEM
format. This file may also contain the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server
private DSA key. See <a href="postconf.5.html#smtpd_tls_dcert_file">smtpd_tls_dcert_file</a> for further details.
</p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_dh1024_param_file">tlsproxy_tls_dh1024_param_file</a>
(default: $<a href="postconf.5.html#smtpd_tls_dh1024_param_file">smtpd_tls_dh1024_param_file</a>)</b></DT><DD>
<p> File with DH parameters that the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server
should use with non-export EDH ciphers. See <a href="postconf.5.html#smtpd_tls_dh1024_param_file">smtpd_tls_dh1024_param_file</a>
for further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_dh512_param_file">tlsproxy_tls_dh512_param_file</a>
(default: $<a href="postconf.5.html#smtpd_tls_dh512_param_file">smtpd_tls_dh512_param_file</a>)</b></DT><DD>
<p> File with DH parameters that the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server
should use with export-grade EDH ciphers. See <a href="postconf.5.html#smtpd_tls_dh512_param_file">smtpd_tls_dh512_param_file</a>
for further details. The default SMTP server cipher grade is
"medium" with Postfix releases after the middle of 2015, and as a
result export-grade cipher suites are by default not used. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_dkey_file">tlsproxy_tls_dkey_file</a>
(default: $<a href="postconf.5.html#smtpd_tls_dkey_file">smtpd_tls_dkey_file</a>)</b></DT><DD>
<p> File with the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server DSA private key in PEM
format. This file may be combined with the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a>
server DSA certificate file specified with $<a href="postconf.5.html#smtpd_tls_dcert_file">smtpd_tls_dcert_file</a>.
See <a href="postconf.5.html#smtpd_tls_dkey_file">smtpd_tls_dkey_file</a> for further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_eccert_file">tlsproxy_tls_eccert_file</a>
(default: $<a href="postconf.5.html#smtpd_tls_eccert_file">smtpd_tls_eccert_file</a>)</b></DT><DD>
<p> File with the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server ECDSA certificate in
PEM format. This file may also contain the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a>
server private ECDSA key. See <a href="postconf.5.html#smtpd_tls_eccert_file">smtpd_tls_eccert_file</a> for further
details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_eckey_file">tlsproxy_tls_eckey_file</a>
(default: $<a href="postconf.5.html#smtpd_tls_eckey_file">smtpd_tls_eckey_file</a>)</b></DT><DD>
<p> File with the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server ECDSA private key in
PEM format. This file may be combined with the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a>
server ECDSA certificate file specified with $<a href="postconf.5.html#smtpd_tls_eccert_file">smtpd_tls_eccert_file</a>.
See <a href="postconf.5.html#smtpd_tls_eckey_file">smtpd_tls_eckey_file</a> for further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_eecdh_grade">tlsproxy_tls_eecdh_grade</a>
(default: $<a href="postconf.5.html#smtpd_tls_eecdh_grade">smtpd_tls_eecdh_grade</a>)</b></DT><DD>
<p> The Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server security grade for ephemeral
elliptic-curve Diffie-Hellman (EECDH) key exchange. See
<a href="postconf.5.html#smtpd_tls_eecdh_grade">smtpd_tls_eecdh_grade</a> for further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_exclude_ciphers">tlsproxy_tls_exclude_ciphers</a>
(default: $<a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a>)</b></DT><DD>
<p> List of ciphers or cipher types to exclude from the <a href="tlsproxy.8.html">tlsproxy(8)</a>
server cipher list at all TLS security levels. See
<a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> for further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_fingerprint_digest">tlsproxy_tls_fingerprint_digest</a>
(default: $<a href="postconf.5.html#smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a>)</b></DT><DD>
<p> The message digest algorithm to construct remote SMTP
client-certificate
fingerprints. See <a href="postconf.5.html#smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a> for further details.
</p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_key_file">tlsproxy_tls_key_file</a>
(default: $<a href="postconf.5.html#smtpd_tls_key_file">smtpd_tls_key_file</a>)</b></DT><DD>
<p> File with the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server RSA private key in PEM
format. This file may be combined with the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a>
server RSA certificate file specified with $<a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a>.
See <a href="postconf.5.html#smtpd_tls_key_file">smtpd_tls_key_file</a> for further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_loglevel">tlsproxy_tls_loglevel</a>
(default: $<a href="postconf.5.html#smtpd_tls_loglevel">smtpd_tls_loglevel</a>)</b></DT><DD>
<p> Enable additional Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server logging of TLS
activity. Each logging level also includes the information that
is logged at a lower logging level. See <a href="postconf.5.html#smtpd_tls_loglevel">smtpd_tls_loglevel</a> for
further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_mandatory_ciphers">tlsproxy_tls_mandatory_ciphers</a>
(default: $<a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>)</b></DT><DD>
<p> The minimum TLS cipher grade that the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server
will use with mandatory TLS encryption. See <a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>
for further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_mandatory_exclude_ciphers">tlsproxy_tls_mandatory_exclude_ciphers</a>
(default: $<a href="postconf.5.html#smtpd_tls_mandatory_exclude_ciphers">smtpd_tls_mandatory_exclude_ciphers</a>)</b></DT><DD>
<p> Additional list of ciphers or cipher types to exclude from the
<a href="tlsproxy.8.html">tlsproxy(8)</a> server cipher list at mandatory TLS security levels.
See <a href="postconf.5.html#smtpd_tls_mandatory_exclude_ciphers">smtpd_tls_mandatory_exclude_ciphers</a> for further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_mandatory_protocols">tlsproxy_tls_mandatory_protocols</a>
(default: $<a href="postconf.5.html#smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a>)</b></DT><DD>
<p> The SSL/TLS protocols accepted by the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server
with mandatory TLS encryption. If the list is empty, the server
supports all available SSL/TLS protocol versions. See
<a href="postconf.5.html#smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a> for further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_protocols">tlsproxy_tls_protocols</a>
(default: $<a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a>)</b></DT><DD>
<p> List of TLS protocols that the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server will
exclude or include with opportunistic TLS encryption. See
<a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a> for further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_req_ccert">tlsproxy_tls_req_ccert</a>
(default: $<a href="postconf.5.html#smtpd_tls_req_ccert">smtpd_tls_req_ccert</a>)</b></DT><DD>
<p> With mandatory TLS encryption, require a trusted remote SMTP
client certificate in order to allow TLS connections to proceed.
See <a href="postconf.5.html#smtpd_tls_req_ccert">smtpd_tls_req_ccert</a> for further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_security_level">tlsproxy_tls_security_level</a>
(default: $<a href="postconf.5.html#smtpd_tls_security_level">smtpd_tls_security_level</a>)</b></DT><DD>
<p> The SMTP TLS security level for the Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server;
when a non-empty value is specified, this overrides the obsolete
parameters <a href="postconf.5.html#smtpd_use_tls">smtpd_use_tls</a> and <a href="postconf.5.html#smtpd_enforce_tls">smtpd_enforce_tls</a>. See
<a href="postconf.5.html#smtpd_tls_security_level">smtpd_tls_security_level</a> for further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_tls_session_cache_timeout">tlsproxy_tls_session_cache_timeout</a>
(default: $<a href="postconf.5.html#smtpd_tls_session_cache_timeout">smtpd_tls_session_cache_timeout</a>)</b></DT><DD>
<p> Obsolete expiration time of Postfix <a href="tlsproxy.8.html">tlsproxy(8)</a> server TLS session
cache information. Since the cache is shared with <a href="smtpd.8.html">smtpd(8)</a> and managed
by <a href="tlsmgr.8.html">tlsmgr(8)</a>, there is only one expiration time for the SMTP server cache
shared by all three services, namely <a href="postconf.5.html#smtpd_tls_session_cache_timeout">smtpd_tls_session_cache_timeout</a>. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_use_tls">tlsproxy_use_tls</a>
(default: $<a href="postconf.5.html#smtpd_use_tls">smtpd_use_tls</a>)</b></DT><DD>
<p> Opportunistic TLS: announce STARTTLS support to remote SMTP clients,
but do not require that clients use TLS encryption. See <a href="postconf.5.html#smtpd_use_tls">smtpd_use_tls</a>
for further details. </p>
<p> This feature is available in Postfix 2.8 and later. </p>
</DD>
<DT><b><a name="tlsproxy_watchdog_timeout">tlsproxy_watchdog_timeout</a>
(default: 10s)</b></DT><DD>
<p> How much time a <a href="tlsproxy.8.html">tlsproxy(8)</a> process may take to process local
or remote I/O before it is terminated by a built-in watchdog timer.
This is a safety mechanism that prevents <a href="tlsproxy.8.html">tlsproxy(8)</a> from becoming
non-responsive due to a bug in Postfix itself or in system software.
To avoid false alarms and unnecessary cache corruption this limit
cannot be set under 10s. </p>
<p> Specify a non-zero time value (an integral value plus an optional
one-letter suffix that specifies the time unit). Time units: s
(seconds), m (minutes), h (hours), d (days), w (weeks). </p>
<p> This feature is available in Postfix 2.8. </p>
</DD>
<DT><b><a name="trace_service_name">trace_service_name</a>
(default: trace)</b></DT><DD>
<p>
The name of the trace service. This service is implemented by the
<a href="bounce.8.html">bounce(8)</a> daemon and maintains a record
of mail deliveries and produces a mail delivery report when verbose
delivery is requested with "<b>sendmail -v</b>".
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="transport_delivery_slot_cost">transport_delivery_slot_cost</a>
(default: $<a href="postconf.5.html#default_delivery_slot_cost">default_delivery_slot_cost</a>)</b></DT><DD>
<p> A transport-specific override for the <a href="postconf.5.html#default_delivery_slot_cost">default_delivery_slot_cost</a>
parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of
the message delivery transport. </p>
<p> Note: <a href="postconf.5.html#transport_delivery_slot_cost"><i>transport</i>_delivery_slot_cost</a> parameters will not
show up in "postconf" command output before Postfix version 2.9.
This limitation applies to many parameters whose name is a combination
of a <a href="master.5.html">master.cf</a> service name and a built-in suffix (in this case:
"_delivery_slot_cost"). </p>
</DD>
<DT><b><a name="transport_delivery_slot_discount">transport_delivery_slot_discount</a>
(default: $<a href="postconf.5.html#default_delivery_slot_discount">default_delivery_slot_discount</a>)</b></DT><DD>
<p> A transport-specific override for the <a href="postconf.5.html#default_delivery_slot_discount">default_delivery_slot_discount</a>
parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of
the message delivery transport. </p>
<p> Note: <a href="postconf.5.html#transport_delivery_slot_discount"><i>transport</i>_delivery_slot_discount</a> parameters will
not show up in "postconf" command output before Postfix version
2.9. This limitation applies to many parameters whose name is a
combination of a <a href="master.5.html">master.cf</a> service name and a built-in suffix (in
this case: "_delivery_slot_discount"). </p>
</DD>
<DT><b><a name="transport_delivery_slot_loan">transport_delivery_slot_loan</a>
(default: $<a href="postconf.5.html#default_delivery_slot_loan">default_delivery_slot_loan</a>)</b></DT><DD>
<p> A transport-specific override for the <a href="postconf.5.html#default_delivery_slot_loan">default_delivery_slot_loan</a>
parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of
the message delivery transport. </p>
<p> Note: <a href="postconf.5.html#transport_delivery_slot_loan"><i>transport</i>_delivery_slot_loan</a> parameters will not
show up in "postconf" command output before Postfix version 2.9.
This limitation applies to many parameters whose name is a combination
of a <a href="master.5.html">master.cf</a> service name and a built-in suffix (in this case:
"_delivery_slot_loan"). </p>
</DD>
<DT><b><a name="transport_destination_concurrency_failed_cohort_limit">transport_destination_concurrency_failed_cohort_limit</a>
(default: $<a href="postconf.5.html#default_destination_concurrency_failed_cohort_limit">default_destination_concurrency_failed_cohort_limit</a>)</b></DT><DD>
<p> A transport-specific override for the
<a href="postconf.5.html#default_destination_concurrency_failed_cohort_limit">default_destination_concurrency_failed_cohort_limit</a> parameter value,
where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of the message delivery
transport. </p>
<p> Note: some <a href="postconf.5.html#transport_destination_concurrency_failed_cohort_limit"><i>transport</i>_destination_concurrency_failed_cohort_limit</a>
parameters will not show up in "postconf" command output before
Postfix version 2.9. This limitation applies to many parameters
whose name is a combination of a <a href="master.5.html">master.cf</a> service name and a
built-in suffix (in this case:
"_destination_concurrency_failed_cohort_limit"). </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="transport_destination_concurrency_limit">transport_destination_concurrency_limit</a>
(default: $<a href="postconf.5.html#default_destination_concurrency_limit">default_destination_concurrency_limit</a>)</b></DT><DD>
<p> A transport-specific override for the
<a href="postconf.5.html#default_destination_concurrency_limit">default_destination_concurrency_limit</a> parameter value, where
<i>transport</i> is the <a href="master.5.html">master.cf</a> name of the message delivery
transport. </p>
<p> Note: some <a href="postconf.5.html#transport_destination_concurrency_limit"><i>transport</i>_destination_concurrency_limit</a>
parameters will not show up in "postconf" command output before
Postfix version 2.9. This limitation applies to many parameters
whose name is a combination of a <a href="master.5.html">master.cf</a> service name and a
built-in suffix (in this case: "_destination_concurrency_limit").
</p>
</DD>
<DT><b><a name="transport_destination_concurrency_negative_feedback">transport_destination_concurrency_negative_feedback</a>
(default: $<a href="postconf.5.html#default_destination_concurrency_negative_feedback">default_destination_concurrency_negative_feedback</a>)</b></DT><DD>
<p> A transport-specific override for the
<a href="postconf.5.html#default_destination_concurrency_negative_feedback">default_destination_concurrency_negative_feedback</a> parameter value,
where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of the message delivery
transport. </p>
<p> Note: some <a href="postconf.5.html#transport_destination_concurrency_negative_feedback"><i>transport</i>_destination_concurrency_negative_feedback</a>
parameters will not show up in "postconf" command output before
Postfix version 2.9. This limitation applies to many parameters
whose name is a combination of a <a href="master.5.html">master.cf</a> service name and a
built-in suffix (in this case:
"_destination_concurrency_negative_feedback"). </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="transport_destination_concurrency_positive_feedback">transport_destination_concurrency_positive_feedback</a>
(default: $<a href="postconf.5.html#default_destination_concurrency_positive_feedback">default_destination_concurrency_positive_feedback</a>)</b></DT><DD>
<p> A transport-specific override for the
<a href="postconf.5.html#default_destination_concurrency_positive_feedback">default_destination_concurrency_positive_feedback</a> parameter value,
where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of the message delivery
transport. </p>
<p> Note: some <a href="postconf.5.html#transport_destination_concurrency_positive_feedback"><i>transport</i>_destination_concurrency_positive_feedback</a>
parameters will not show up in "postconf" command output before
Postfix version 2.9. This limitation applies to many parameters
whose name is a combination of a <a href="master.5.html">master.cf</a> service name and a
built-in suffix (in this case:
"_destination_concurrency_positive_feedback"). </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="transport_destination_rate_delay">transport_destination_rate_delay</a>
(default: $<a href="postconf.5.html#default_destination_rate_delay">default_destination_rate_delay</a>)</b></DT><DD>
<p> A transport-specific override for the <a href="postconf.5.html#default_destination_rate_delay">default_destination_rate_delay</a>
parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of
the message delivery transport. </p>
<p> Note: some <a href="postconf.5.html#transport_destination_rate_delay"><i>transport</i>_destination_rate_delay</a> parameters
will not show up in "postconf" command output before Postfix version
2.9. This limitation applies to many parameters whose name is a
combination of a <a href="master.5.html">master.cf</a> service name and a built-in suffix (in
this case: "_destination_rate_delay"). </p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="transport_destination_recipient_limit">transport_destination_recipient_limit</a>
(default: $<a href="postconf.5.html#default_destination_recipient_limit">default_destination_recipient_limit</a>)</b></DT><DD>
<p> A transport-specific override for the
<a href="postconf.5.html#default_destination_recipient_limit">default_destination_recipient_limit</a> parameter value, where
<i>transport</i> is the <a href="master.5.html">master.cf</a> name of the message delivery
transport. </p>
<p> Note: some <a href="postconf.5.html#transport_destination_recipient_limit"><i>transport</i>_destination_recipient_limit</a> parameters
will not show up in "postconf" command output before Postfix version
2.9. This limitation applies to many parameters whose name is a
combination of a <a href="master.5.html">master.cf</a> service name and a built-in suffix (in
this case: "_destination_recipient_limit"). </p>
</DD>
<DT><b><a name="transport_extra_recipient_limit">transport_extra_recipient_limit</a>
(default: $<a href="postconf.5.html#default_extra_recipient_limit">default_extra_recipient_limit</a>)</b></DT><DD>
<p> A transport-specific override for the <a href="postconf.5.html#default_extra_recipient_limit">default_extra_recipient_limit</a>
parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of
the message delivery transport. </p>
<p> Note: <a href="postconf.5.html#transport_extra_recipient_limit"><i>transport</i>_extra_recipient_limit</a> parameters will
not show up in "postconf" command output before Postfix version
2.9. This limitation applies to many parameters whose name is a
combination of a <a href="master.5.html">master.cf</a> service name and a built-in suffix (in
this case: "_extra_recipient_limit"). </p>
</DD>
<DT><b><a name="transport_initial_destination_concurrency">transport_initial_destination_concurrency</a>
(default: $<a href="postconf.5.html#initial_destination_concurrency">initial_destination_concurrency</a>)</b></DT><DD>
<p> A transport-specific override for the <a href="postconf.5.html#initial_destination_concurrency">initial_destination_concurrency</a>
parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of
the message delivery transport. </p>
<p> Note: some <a href="postconf.5.html#transport_initial_destination_concurrency"><i>transport</i>_initial_destination_concurrency</a>
parameters will not show up in "postconf" command output before
Postfix version 2.9. This limitation applies to many parameters
whose name is a combination of a <a href="master.5.html">master.cf</a> service name and a
built-in suffix (in this case: "_initial_destination_concurrency").
</p>
<p> This feature is available in Postfix 2.5 and later. </p>
</DD>
<DT><b><a name="transport_maps">transport_maps</a>
(default: empty)</b></DT><DD>
<p>
Optional lookup tables with mappings from recipient address to
(message delivery transport, next-hop destination). See <a href="transport.5.html">transport(5)</a>
for details.
</p>
<p>
Specify zero or more "<a href="DATABASE_README.html">type:table</a>" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found. If you use this
feature with local files, run "<b>postmap /etc/postfix/transport</b>"
after making a change. </p>
<p> Pattern matching of domain names is controlled by the presence
or absence of "<a href="postconf.5.html#transport_maps">transport_maps</a>" in the <a href="postconf.5.html#parent_domain_matches_subdomains">parent_domain_matches_subdomains</a>
parameter value. </p>
<p> For safety reasons, as of Postfix 2.3 this feature does not
allow $number substitutions in regular expression maps. </p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#transport_maps">transport_maps</a> = <a href="DATABASE_README.html#types">dbm</a>:/etc/postfix/transport
<a href="postconf.5.html#transport_maps">transport_maps</a> = <a href="DATABASE_README.html#types">hash</a>:/etc/postfix/transport
</pre>
</DD>
<DT><b><a name="transport_minimum_delivery_slots">transport_minimum_delivery_slots</a>
(default: $<a href="postconf.5.html#default_minimum_delivery_slots">default_minimum_delivery_slots</a>)</b></DT><DD>
<p> A transport-specific override for the <a href="postconf.5.html#default_minimum_delivery_slots">default_minimum_delivery_slots</a>
parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of
the message delivery transport. </p>
<p> Note: <a href="postconf.5.html#transport_minimum_delivery_slots"><i>transport</i>_minimum_delivery_slots</a> parameters will
not show up in "postconf" command output before Postfix version
2.9. This limitation applies to many parameters whose name is a
combination of a <a href="master.5.html">master.cf</a> service name and a built-in suffix (in
this case: "_minimum_delivery_slots"). </p>
</DD>
<DT><b><a name="transport_recipient_limit">transport_recipient_limit</a>
(default: $<a href="postconf.5.html#default_recipient_limit">default_recipient_limit</a>)</b></DT><DD>
<p> A transport-specific override for the <a href="postconf.5.html#default_recipient_limit">default_recipient_limit</a>
parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of
the message delivery transport. </p>
<p> Note: some <a href="postconf.5.html#transport_recipient_limit"><i>transport</i>_recipient_limit</a> parameters will not
show up in "postconf" command output before Postfix version 2.9.
This limitation applies to many parameters whose name is a combination
of a <a href="master.5.html">master.cf</a> service name and a built-in suffix (in this case:
"_recipient_limit"). </p>
</DD>
<DT><b><a name="transport_recipient_refill_delay">transport_recipient_refill_delay</a>
(default: $<a href="postconf.5.html#default_recipient_refill_delay">default_recipient_refill_delay</a>)</b></DT><DD>
<p> A transport-specific override for the <a href="postconf.5.html#default_recipient_refill_delay">default_recipient_refill_delay</a>
parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of
the message delivery transport. </p>
<p> Note: <a href="postconf.5.html#transport_recipient_refill_delay"><i>transport</i>_recipient_refill_delay</a> parameters will
not show up in "postconf" command output before Postfix version
2.9. This limitation applies to many parameters whose name is a
combination of a <a href="master.5.html">master.cf</a> service name and a built-in suffix (in
this case: "_recipient_refill_delay"). </p>
<p> This feature is available in Postfix 2.4 and later. </p>
</DD>
<DT><b><a name="transport_recipient_refill_limit">transport_recipient_refill_limit</a>
(default: $<a href="postconf.5.html#default_recipient_refill_limit">default_recipient_refill_limit</a>)</b></DT><DD>
<p> A transport-specific override for the <a href="postconf.5.html#default_recipient_refill_limit">default_recipient_refill_limit</a>
parameter value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of
the message delivery transport. </p>
<p> Note: <a href="postconf.5.html#transport_recipient_refill_limit"><i>transport</i>_recipient_refill_limit</a> parameters will
not show up in "postconf" command output before Postfix version
2.9. This limitation applies to many parameters whose name is a
combination of a <a href="master.5.html">master.cf</a> service name and a built-in suffix (in
this case: "_recipient_refill_limit"). </p>
<p> This feature is available in Postfix 2.4 and later. </p>
</DD>
<DT><b><a name="transport_retry_time">transport_retry_time</a>
(default: 60s)</b></DT><DD>
<p>
The time between attempts by the Postfix queue manager to contact
a malfunctioning message delivery transport.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="transport_time_limit">transport_time_limit</a>
(default: $<a href="postconf.5.html#command_time_limit">command_time_limit</a>)</b></DT><DD>
<p> A transport-specific override for the <a href="postconf.5.html#command_time_limit">command_time_limit</a> parameter
value, where <i>transport</i> is the <a href="master.5.html">master.cf</a> name of the message
delivery transport. </p>
<p> Note: <a href="postconf.5.html#transport_time_limit"><i>transport</i>_time_limit</a> parameters will not show up
in "postconf" command output before Postfix version 2.9. This
limitation applies to many parameters whose name is a combination
of a <a href="master.5.html">master.cf</a> service name and a built-in suffix (in this case:
"_time_limit"). </p>
</DD>
<DT><b><a name="transport_transport_rate_delay">transport_transport_rate_delay</a>
(default: $<a href="postconf.5.html#default_transport_rate_delay">default_transport_rate_delay</a>)</b></DT><DD>
<p> A transport-specific override for the <a href="postconf.5.html#default_transport_rate_delay">default_transport_rate_delay</a>
parameter value, where the initial <i>transport</i> in the parameter
name is the <a href="master.5.html">master.cf</a> name of the message delivery transport. </p>
</DD>
<DT><b><a name="trigger_timeout">trigger_timeout</a>
(default: 10s)</b></DT><DD>
<p>
The time limit for sending a trigger to a Postfix daemon (for
example, the <a href="pickup.8.html">pickup(8)</a> or <a href="qmgr.8.html">qmgr(8)</a> daemon). This time limit prevents
programs from getting stuck when the mail system is under heavy
load.
</p>
<p>
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
</p>
</DD>
<DT><b><a name="undisclosed_recipients_header">undisclosed_recipients_header</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
Message header that the Postfix <a href="cleanup.8.html">cleanup(8)</a> server inserts when a
message contains no To: or Cc: message header. With Postfix 2.8
and later, the default value is empty. With Postfix 2.4-2.7,
specify an empty value to disable this feature. </p>
<p> Example: </p>
<pre>
# Default value before Postfix 2.8.
# Note: the ":" and ";" are both required.
<a href="postconf.5.html#undisclosed_recipients_header">undisclosed_recipients_header</a> = To: undisclosed-recipients:;
</pre>
</DD>
<DT><b><a name="unknown_address_reject_code">unknown_address_reject_code</a>
(default: 450)</b></DT><DD>
<p>
The numerical response code when the Postfix SMTP server rejects a
sender or recipient address because its domain is unknown. This
is one of the possible replies from the restrictions
<a href="postconf.5.html#reject_unknown_sender_domain">reject_unknown_sender_domain</a> and <a href="postconf.5.html#reject_unknown_recipient_domain">reject_unknown_recipient_domain</a>.
</p>
<p>
Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc5321">RFC 5321</a>.
</p>
</DD>
<DT><b><a name="unknown_address_tempfail_action">unknown_address_tempfail_action</a>
(default: $<a href="postconf.5.html#reject_tempfail_action">reject_tempfail_action</a>)</b></DT><DD>
<p> The Postfix SMTP server's action when <a href="postconf.5.html#reject_unknown_sender_domain">reject_unknown_sender_domain</a>
or <a href="postconf.5.html#reject_unknown_recipient_domain">reject_unknown_recipient_domain</a> fail due to a temporary error
condition. Specify "defer" to defer the remote SMTP client request
immediately. With the default "<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>" action, the Postfix
SMTP server continues to look for opportunities to reject mail, and
defers the client request only if it would otherwise be accepted.
</p>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="unknown_client_reject_code">unknown_client_reject_code</a>
(default: 450)</b></DT><DD>
<p>
The numerical Postfix SMTP server response code when a client
without valid address <=> name mapping is rejected by the
<a href="postconf.5.html#reject_unknown_client_hostname">reject_unknown_client_hostname</a> restriction. The SMTP server always replies
with 450 when the mapping failed due to a temporary error condition.
</p>
<p>
Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc5321">RFC 5321</a>.
</p>
</DD>
<DT><b><a name="unknown_helo_hostname_tempfail_action">unknown_helo_hostname_tempfail_action</a>
(default: $<a href="postconf.5.html#reject_tempfail_action">reject_tempfail_action</a>)</b></DT><DD>
<p> The Postfix SMTP server's action when <a href="postconf.5.html#reject_unknown_helo_hostname">reject_unknown_helo_hostname</a>
fails due to an temporary error condition. Specify "defer" to defer
the remote SMTP client request immediately. With the default
"<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>" action, the Postfix SMTP server continues to look
for opportunities to reject mail, and defers the client request
only if it would otherwise be accepted. </p>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="unknown_hostname_reject_code">unknown_hostname_reject_code</a>
(default: 450)</b></DT><DD>
<p>
The numerical Postfix SMTP server response code when the hostname
specified with the HELO or EHLO command is rejected by the
<a href="postconf.5.html#reject_unknown_helo_hostname">reject_unknown_helo_hostname</a> restriction.
</p>
<p>
Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc5321">RFC 5321</a>.
</p>
</DD>
<DT><b><a name="unknown_local_recipient_reject_code">unknown_local_recipient_reject_code</a>
(default: 550)</b></DT><DD>
<p>
The numerical Postfix SMTP server response code when a recipient
address is local, and $<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> specifies a list of
lookup tables that does not match the recipient. A recipient
address is local when its domain matches $<a href="postconf.5.html#mydestination">mydestination</a>,
$<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a> or $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a>.
</p>
<p>
The default setting is 550 (reject mail) but it is safer to initially
use 450 (try again later) so you have time to find out if your
<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> settings are OK.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#unknown_local_recipient_reject_code">unknown_local_recipient_reject_code</a> = 450
</pre>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="unknown_relay_recipient_reject_code">unknown_relay_recipient_reject_code</a>
(default: 550)</b></DT><DD>
<p>
The numerical Postfix SMTP server reply code when a recipient
address matches $<a href="postconf.5.html#relay_domains">relay_domains</a>, and <a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a> specifies
a list of lookup tables that does not match the recipient address.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="unknown_virtual_alias_reject_code">unknown_virtual_alias_reject_code</a>
(default: 550)</b></DT><DD>
<p>
The Postfix SMTP server reply code when a recipient address matches
$<a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a>, and $<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a> specifies a list
of lookup tables that does not match the recipient address.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="unknown_virtual_mailbox_reject_code">unknown_virtual_mailbox_reject_code</a>
(default: 550)</b></DT><DD>
<p>
The Postfix SMTP server reply code when a recipient address matches
$<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>, and $<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a> specifies a list
of lookup tables that does not match the recipient address.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="unverified_recipient_defer_code">unverified_recipient_defer_code</a>
(default: 450)</b></DT><DD>
<p>
The numerical Postfix SMTP server response when a recipient address
probe fails due to a temporary error condition.
</p>
<p>
Unlike elsewhere in Postfix, you can specify 250 in order to
accept the address anyway.
</p>
<p>
Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc5321">RFC 5321</a>.
</p>
<p>
This feature is available in Postfix 2.6 and later.
</p>
</DD>
<DT><b><a name="unverified_recipient_reject_code">unverified_recipient_reject_code</a>
(default: 450)</b></DT><DD>
<p>
The numerical Postfix SMTP server response when a recipient address
is rejected by the <a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipient</a> restriction.
</p>
<p>
Unlike elsewhere in Postfix, you can specify 250 in order to
accept the address anyway.
</p>
<p>
Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc5321">RFC 5321</a>.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="unverified_recipient_reject_reason">unverified_recipient_reject_reason</a>
(default: empty)</b></DT><DD>
<p> The Postfix SMTP server's reply when rejecting mail with
<a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipient</a>. Do not include the numeric SMTP reply
code or the enhanced status code. By default, the response includes
actual address verification details.
<p> Example: </p>
<pre>
<a href="postconf.5.html#unverified_recipient_reject_reason">unverified_recipient_reject_reason</a> = Recipient address lookup failed
</pre>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="unverified_recipient_tempfail_action">unverified_recipient_tempfail_action</a>
(default: $<a href="postconf.5.html#reject_tempfail_action">reject_tempfail_action</a>)</b></DT><DD>
<p> The Postfix SMTP server's action when <a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipient</a>
fails due to a temporary error condition. Specify "defer" to defer
the remote SMTP client request immediately. With the default
"<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>" action, the Postfix SMTP server continues to look
for opportunities to reject mail, and defers the client request
only if it would otherwise be accepted. </p>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="unverified_sender_defer_code">unverified_sender_defer_code</a>
(default: 450)</b></DT><DD>
<p>
The numerical Postfix SMTP server response code when a sender address
probe fails due to a temporary error condition.
</p>
<p>
Unlike elsewhere in Postfix, you can specify 250 in order to
accept the address anyway.
</p>
<p>
Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc5321">RFC 5321</a>.
</p>
<p>
This feature is available in Postfix 2.6 and later.
</p>
</DD>
<DT><b><a name="unverified_sender_reject_code">unverified_sender_reject_code</a>
(default: 450)</b></DT><DD>
<p>
The numerical Postfix SMTP server response code when a recipient
address is rejected by the <a href="postconf.5.html#reject_unverified_sender">reject_unverified_sender</a> restriction.
</p>
<p>
Unlike elsewhere in Postfix, you can specify 250 in order to
accept the address anyway.
</p>
<p>
Do not change this unless you have a complete understanding of <a href="http://tools.ietf.org/html/rfc5321">RFC 5321</a>.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="unverified_sender_reject_reason">unverified_sender_reject_reason</a>
(default: empty)</b></DT><DD>
<p> The Postfix SMTP server's reply when rejecting mail with
<a href="postconf.5.html#reject_unverified_sender">reject_unverified_sender</a>. Do not include the numeric SMTP reply
code or the enhanced status code. By default, the response includes
actual address verification details.
<p> Example: </p>
<pre>
<a href="postconf.5.html#unverified_sender_reject_reason">unverified_sender_reject_reason</a> = Sender address lookup failed
</pre>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="unverified_sender_tempfail_action">unverified_sender_tempfail_action</a>
(default: $<a href="postconf.5.html#reject_tempfail_action">reject_tempfail_action</a>)</b></DT><DD>
<p> The Postfix SMTP server's action when <a href="postconf.5.html#reject_unverified_sender">reject_unverified_sender</a>
fails due to a temporary error condition. Specify "defer" to defer
the remote SMTP client request immediately. With the default
"<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>" action, the Postfix SMTP server continues to look
for opportunities to reject mail, and defers the client request
only if it would otherwise be accepted. </p>
<p> This feature is available in Postfix 2.6 and later. </p>
</DD>
<DT><b><a name="verp_delimiter_filter">verp_delimiter_filter</a>
(default: -=+)</b></DT><DD>
<p>
The characters Postfix accepts as VERP delimiter characters on the
Postfix <a href="sendmail.1.html">sendmail(1)</a> command line and in SMTP commands.
</p>
<p>
This feature is available in Postfix 1.1 and later.
</p>
</DD>
<DT><b><a name="virtual_alias_address_length_limit">virtual_alias_address_length_limit</a>
(default: 1000)</b></DT><DD>
<p>
The maximal length of an email address after virtual alias expansion.
This stops virtual aliasing loops that increase the address length
exponentially.
</p>
<p>
This feature is available in Postfix 3.0 and later.
</p>
</DD>
<DT><b><a name="virtual_alias_domains">virtual_alias_domains</a>
(default: $<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a>)</b></DT><DD>
<p> Postfix is final destination for the specified list of virtual
alias domains, that is, domains for which all addresses are aliased
to addresses in other local or remote domains. The SMTP server
validates recipient addresses with $<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a> and rejects
non-existent recipients. See also the <a href="ADDRESS_CLASS_README.html#virtual_alias_class">virtual alias domain</a> class
in the <a href="ADDRESS_CLASS_README.html">ADDRESS_CLASS_README</a> file </p>
<p>
This feature is available in Postfix 2.0 and later. The default
value is backwards compatible with Postfix version 1.1.
</p>
<p>
The default value is $<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a> so that you can keep all
information about <a href="ADDRESS_CLASS_README.html#virtual_alias_class">virtual alias domains</a> in one place. If you have
many users, it is better to separate information that changes more
frequently (virtual address -> local or remote address mapping)
from information that changes less frequently (the list of virtual
domain names).
</p>
<p> Specify a list of host or domain names, "/file/name" or
"<a href="DATABASE_README.html">type:table</a>" patterns, separated by commas and/or whitespace. A
"/file/name" pattern is replaced by its contents; a "<a href="DATABASE_README.html">type:table</a>"
lookup table is matched when a table entry matches a lookup string
(the lookup result is ignored). Continue long lines by starting
the next line with whitespace. Specify "!pattern" to exclude a host
or domain name from the list. The form "!/file/name" is supported
only in Postfix version 2.4 and later. </p>
<p>
See also the <a href="VIRTUAL_README.html">VIRTUAL_README</a> and <a href="ADDRESS_CLASS_README.html">ADDRESS_CLASS_README</a> documents
for further information.
</p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a> = virtual1.tld virtual2.tld
</pre>
</DD>
<DT><b><a name="virtual_alias_expansion_limit">virtual_alias_expansion_limit</a>
(default: 1000)</b></DT><DD>
<p>
The maximal number of addresses that virtual alias expansion produces
from each original recipient.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="virtual_alias_maps">virtual_alias_maps</a>
(default: $<a href="postconf.5.html#virtual_maps">virtual_maps</a>)</b></DT><DD>
<p>
Optional lookup tables that alias specific mail addresses or domains
to other local or remote address. The table format and lookups
are documented in <a href="virtual.5.html">virtual(5)</a>. For an overview of Postfix address
manipulations see the <a href="ADDRESS_REWRITING_README.html">ADDRESS_REWRITING_README</a> document.
</p>
<p>
This feature is available in Postfix 2.0 and later. The default
value is backwards compatible with Postfix version 1.1.
</p>
<p>
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found.
Note: these lookups are recursive.
</p>
<p>
If you use this feature with indexed files, run "<b>postmap
/etc/postfix/virtual</b>" after changing the file.
</p>
<p>
Examples:
</p>
<pre>
<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a> = <a href="DATABASE_README.html#types">dbm</a>:/etc/postfix/virtual
<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a> = <a href="DATABASE_README.html#types">hash</a>:/etc/postfix/virtual
</pre>
</DD>
<DT><b><a name="virtual_alias_recursion_limit">virtual_alias_recursion_limit</a>
(default: 1000)</b></DT><DD>
<p>
The maximal nesting depth of virtual alias expansion. Currently
the recursion limit is applied only to the left branch of the
expansion graph, so the depth of the tree can in the worst case
reach the sum of the expansion and recursion limits. This may
change in the future.
</p>
<p>
This feature is available in Postfix 2.1 and later.
</p>
</DD>
<DT><b><a name="virtual_delivery_status_filter">virtual_delivery_status_filter</a>
(default: $<a href="postconf.5.html#default_delivery_status_filter">default_delivery_status_filter</a>)</b></DT><DD>
<p> Optional filter for the <a href="virtual.8.html">virtual(8)</a> delivery agent to change the
delivery status code or explanatory text of successful or unsuccessful
deliveries. See <a href="postconf.5.html#default_delivery_status_filter">default_delivery_status_filter</a> for details. </p>
<p> This feature is available in Postfix 3.0 and later. </p>
</DD>
<DT><b><a name="virtual_destination_concurrency_limit">virtual_destination_concurrency_limit</a>
(default: $<a href="postconf.5.html#default_destination_concurrency_limit">default_destination_concurrency_limit</a>)</b></DT><DD>
<p> The maximal number of parallel deliveries to the same destination
via the virtual message delivery transport. This limit is enforced
by the queue manager. The message delivery transport name is the
first field in the entry in the <a href="master.5.html">master.cf</a> file. </p>
</DD>
<DT><b><a name="virtual_destination_recipient_limit">virtual_destination_recipient_limit</a>
(default: $<a href="postconf.5.html#default_destination_recipient_limit">default_destination_recipient_limit</a>)</b></DT><DD>
<p> The maximal number of recipients per message for the virtual
message delivery transport. This limit is enforced by the queue
manager. The message delivery transport name is the first field in
the entry in the <a href="master.5.html">master.cf</a> file. </p>
<p> Setting this parameter to a value of 1 changes the meaning of
<a href="postconf.5.html#virtual_destination_concurrency_limit">virtual_destination_concurrency_limit</a> from concurrency per domain
into concurrency per recipient. </p>
</DD>
<DT><b><a name="virtual_gid_maps">virtual_gid_maps</a>
(default: empty)</b></DT><DD>
<p>
Lookup tables with the per-recipient group ID for <a href="virtual.8.html">virtual(8)</a> mailbox
delivery.
</p>
<p> This parameter is specific to the <a href="virtual.8.html">virtual(8)</a> delivery agent.
It does not apply when mail is delivered with a different mail
delivery program. </p>
<p>
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found.
</p>
<p>
In a lookup table, specify a left-hand side of "@domain.tld" to
match any user in the specified domain that does not have a specific
"user@domain.tld" entry.
</p>
<p>
When a recipient address has an optional address extension
(user+foo@domain.tld), the <a href="virtual.8.html">virtual(8)</a> delivery agent looks up
the full address first, and when the lookup fails, it looks up the
unextended address (user@domain.tld).
</p>
<p>
Note 1: for security reasons, the <a href="virtual.8.html">virtual(8)</a> delivery agent disallows
regular expression substitution of $1 etc. in regular expression
lookup tables, because that would open a security hole.
</p>
<p>
Note 2: for security reasons, the <a href="virtual.8.html">virtual(8)</a> delivery agent will
silently ignore requests to use the <a href="proxymap.8.html">proxymap(8)</a> server. Instead
it will open the table directly. Before Postfix version 2.2, the
<a href="virtual.8.html">virtual(8)</a> delivery agent will terminate with a fatal error.
</p>
</DD>
<DT><b><a name="virtual_mailbox_base">virtual_mailbox_base</a>
(default: empty)</b></DT><DD>
<p>
A prefix that the <a href="virtual.8.html">virtual(8)</a> delivery agent prepends to all pathname
results from $<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a> table lookups. This is a safety
measure to ensure that an out of control map doesn't litter the
file system with mailboxes. While <a href="postconf.5.html#virtual_mailbox_base">virtual_mailbox_base</a> could be
set to "/", this setting isn't recommended.
</p>
<p> This parameter is specific to the <a href="virtual.8.html">virtual(8)</a> delivery agent.
It does not apply when mail is delivered with a different mail
delivery program. </p>
<p>
Example:
</p>
<pre>
<a href="postconf.5.html#virtual_mailbox_base">virtual_mailbox_base</a> = /var/mail
</pre>
</DD>
<DT><b><a name="virtual_mailbox_domains">virtual_mailbox_domains</a>
(default: $<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a>)</b></DT><DD>
<p> Postfix is final destination for the specified list of domains;
mail is delivered via the $<a href="postconf.5.html#virtual_transport">virtual_transport</a> mail delivery transport.
By default this is the Postfix <a href="virtual.8.html">virtual(8)</a> delivery agent. The SMTP
server validates recipient addresses with $<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a>
and rejects mail for non-existent recipients. See also the virtual
mailbox domain class in the <a href="ADDRESS_CLASS_README.html">ADDRESS_CLASS_README</a> file. </p>
<p> This parameter expects the same syntax as the <a href="postconf.5.html#mydestination">mydestination</a>
configuration parameter. </p>
<p>
This feature is available in Postfix 2.0 and later. The default
value is backwards compatible with Postfix version 1.1.
</p>
</DD>
<DT><b><a name="virtual_mailbox_limit">virtual_mailbox_limit</a>
(default: 51200000)</b></DT><DD>
<p>
The maximal size in bytes of an individual <a href="virtual.8.html">virtual(8)</a> mailbox or
maildir file, or zero (no limit). </p>
<p> This parameter is specific to the <a href="virtual.8.html">virtual(8)</a> delivery agent.
It does not apply when mail is delivered with a different mail
delivery program. </p>
</DD>
<DT><b><a name="virtual_mailbox_lock">virtual_mailbox_lock</a>
(default: see "postconf -d" output)</b></DT><DD>
<p>
How to lock a UNIX-style <a href="virtual.8.html">virtual(8)</a> mailbox before attempting
delivery. For a list of available file locking methods, use the
"<b>postconf -l</b>" command.
</p>
<p> This parameter is specific to the <a href="virtual.8.html">virtual(8)</a> delivery agent.
It does not apply when mail is delivered with a different mail
delivery program. </p>
<p>
This setting is ignored with <b>maildir</b> style delivery, because
such deliveries are safe without application-level locks.
</p>
<p>
Note 1: the <b>dotlock</b> method requires that the recipient UID
or GID has write access to the parent directory of the recipient's
mailbox file.
</p>
<p>
Note 2: the default setting of this parameter is system dependent.
</p>
</DD>
<DT><b><a name="virtual_mailbox_maps">virtual_mailbox_maps</a>
(default: empty)</b></DT><DD>
<p>
Optional lookup tables with all valid addresses in the domains that
match $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>.
</p>
<p>
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found.
</p>
<p>
In a lookup table, specify a left-hand side of "@domain.tld" to
match any user in the specified domain that does not have a specific
"user@domain.tld" entry.
</p>
<p> The remainder of this text is specific to the <a href="virtual.8.html">virtual(8)</a> delivery
agent. It does not apply when mail is delivered with a different
mail delivery program. </p>
<p>
The <a href="virtual.8.html">virtual(8)</a> delivery agent uses this table to look up the
per-recipient mailbox or maildir pathname. If the lookup result
ends in a slash ("/"), maildir-style delivery is carried out,
otherwise the path is assumed to specify a UNIX-style mailbox file.
Note that $<a href="postconf.5.html#virtual_mailbox_base">virtual_mailbox_base</a> is unconditionally prepended to
this path.
</p>
<p>
When a recipient address has an optional address extension
(user+foo@domain.tld), the <a href="virtual.8.html">virtual(8)</a> delivery agent looks up
the full address first, and when the lookup fails, it looks up the
unextended address (user@domain.tld).
</p>
<p>
Note 1: for security reasons, the <a href="virtual.8.html">virtual(8)</a> delivery agent disallows
regular expression substitution of $1 etc. in regular expression
lookup tables, because that would open a security hole.
</p>
<p>
Note 2: for security reasons, the <a href="virtual.8.html">virtual(8)</a> delivery agent will
silently ignore requests to use the <a href="proxymap.8.html">proxymap(8)</a> server. Instead
it will open the table directly. Before Postfix version 2.2, the
<a href="virtual.8.html">virtual(8)</a> delivery agent will terminate with a fatal error.
</p>
</DD>
<DT><b><a name="virtual_maps">virtual_maps</a>
(default: empty)</b></DT><DD>
<p> Optional lookup tables with a) names of domains for which all
addresses are aliased to addresses in other local or remote domains,
and b) addresses that are aliased to addresses in other local or
remote domains. Available before Postfix version 2.0. With Postfix
version 2.0 and later, this is replaced by separate controls: <a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a>
and <a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a>. </p>
</DD>
<DT><b><a name="virtual_minimum_uid">virtual_minimum_uid</a>
(default: 100)</b></DT><DD>
<p>
The minimum user ID value that the <a href="virtual.8.html">virtual(8)</a> delivery agent accepts
as a result from $<a href="postconf.5.html#virtual_uid_maps">virtual_uid_maps</a> table lookup. Returned
values less than this will be rejected, and the message will be
deferred.
</p>
<p> This parameter is specific to the <a href="virtual.8.html">virtual(8)</a> delivery agent.
It does not apply when mail is delivered with a different mail
delivery program. </p>
</DD>
<DT><b><a name="virtual_transport">virtual_transport</a>
(default: virtual)</b></DT><DD>
<p>
The default mail delivery transport and next-hop destination for
final delivery to domains listed with $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>.
This information can be overruled with the <a href="transport.5.html">transport(5)</a> table.
</p>
<p>
Specify a string of the form <i>transport:nexthop</i>, where <i>transport</i>
is the name of a mail delivery transport defined in <a href="master.5.html">master.cf</a>.
The <i>:nexthop</i> destination is optional; its syntax is documented
in the manual page of the corresponding delivery agent.
</p>
<p>
This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="virtual_uid_maps">virtual_uid_maps</a>
(default: empty)</b></DT><DD>
<p>
Lookup tables with the per-recipient user ID that the <a href="virtual.8.html">virtual(8)</a>
delivery agent uses while writing to the recipient's mailbox.
</p>
<p> This parameter is specific to the <a href="virtual.8.html">virtual(8)</a> delivery agent.
It does not apply when mail is delivered with a different mail
delivery program. </p>
<p>
Specify zero or more "type:name" lookup tables, separated by
whitespace or comma. Tables will be searched in the specified order
until a match is found.
</p>
<p>
In a lookup table, specify a left-hand side of "@domain.tld"
to match any user in the specified domain that does not have a
specific "user@domain.tld" entry.
</p>
<p>
When a recipient address has an optional address extension
(user+foo@domain.tld), the <a href="virtual.8.html">virtual(8)</a> delivery agent looks up
the full address first, and when the lookup fails, it looks up the
unextended address (user@domain.tld).
</p>
<p>
Note 1: for security reasons, the <a href="virtual.8.html">virtual(8)</a> delivery agent disallows
regular expression substitution of $1 etc. in regular expression
lookup tables, because that would open a security hole.
</p>
<p>
Note 2: for security reasons, the <a href="virtual.8.html">virtual(8)</a> delivery agent will
silently ignore requests to use the <a href="proxymap.8.html">proxymap(8)</a> server. Instead
it will open the table directly. Before Postfix version 2.2, the
<a href="virtual.8.html">virtual(8)</a> delivery agent will terminate with a fatal error.
</p>
</DD>
</dl>
</body>
</html>
|