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<!doctype html public "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
<html> <head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<title> Postfix manual - canonical(5) </title>
</head> <body> <pre>
CANONICAL(5)                                                      CANONICAL(5)

<b>NAME</b>
       canonical - Postfix canonical table format

<b>SYNOPSIS</b>
       <b>postmap /etc/postfix/canonical</b>

       <b>postmap -q "</b><i>string</i><b>" /etc/postfix/canonical</b>

       <b>postmap -q - /etc/postfix/canonical</b> &lt;<i>inputfile</i>

<b>DESCRIPTION</b>
       The  optional <a href="canonical.5.html"><b>canonical</b>(5)</a> table specifies an address mapping for local
       and non-local addresses. The mapping is used by the <a href="cleanup.8.html"><b>cleanup</b>(8)</a>  daemon,
       before  mail  is  stored into the queue.  The address mapping is recur-
       sive.

       Normally, the <a href="canonical.5.html"><b>canonical</b>(5)</a> table is  specified  as  a  text  file  that
       serves as input to the <a href="postmap.1.html"><b>postmap</b>(1)</a> command.  The result, an indexed file
       in <b>dbm</b> or <b>db</b> format, is used for fast searching  by  the  mail  system.
       Execute  the  command  "<b>postmap  /etc/postfix/canonical</b>"  to rebuild an
       indexed file after changing the corresponding text file.

       When the table is provided via other means such as NIS,  LDAP  or  SQL,
       the same lookups are done as for ordinary indexed files.

       Alternatively,  the  table  can be provided as a regular-expression map
       where patterns are given as regular  expressions,  or  lookups  can  be
       directed to TCP-based server. In those cases, the lookups are done in a
       slightly different way as described  below  under  "REGULAR  EXPRESSION
       TABLES" or "TCP-BASED TABLES".

       By  default  the  <a href="canonical.5.html"><b>canonical</b>(5)</a>  mapping  affects  both  message  header
       addresses (i.e. addresses that  appear  inside  messages)  and  message
       envelope  addresses  (for  example, the addresses that are used in SMTP
       protocol commands).  This  is  controlled  with  the  <b><a href="postconf.5.html#canonical_classes">canonical_classes</a></b>
       parameter.

       NOTE:  Postfix  versions  2.2  and  later  rewrite message headers from
       remote SMTP clients only if the  client  matches  the  <a href="postconf.5.html#local_header_rewrite_clients">local_header_re</a>-
       <a href="postconf.5.html#local_header_rewrite_clients">write_clients</a> parameter, or if the <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> config-
       uration parameter specifies a non-empty  value.  To  get  the  behavior
       before    Postfix    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".

       Typically, one would use the <a href="canonical.5.html"><b>canonical</b>(5)</a> table to replace login  names
       by <i>Firstname.Lastname</i>, or to clean up addresses produced by legacy mail
       systems.

       The <a href="canonical.5.html"><b>canonical</b>(5)</a> mapping is not to be confused with <i>virtual alias</i>  sup-
       port  or  with  local  aliasing.  To change the destination but not the
       headers, use the <a href="virtual.5.html"><b>virtual</b>(5)</a> or <a href="aliases.5.html"><b>aliases</b>(5)</a> map instead.

<b>CASE FOLDING</b>
       The search string is folded to lowercase before database lookup. As  of
       Postfix  2.3,  the search string is not case folded with database types
       such as <a href="regexp_table.5.html">regexp</a>: or <a href="pcre_table.5.html">pcre</a>: whose lookup fields can match both  upper  and
       lower case.

<b>TABLE FORMAT</b>
       The input format for the <a href="postmap.1.html"><b>postmap</b>(1)</a> command is as follows:

       <i>pattern address</i>
              When  <i>pattern</i>  matches  a mail address, replace it by the corre-
              sponding <i>address</i>.

       blank lines and comments
              Empty lines and whitespace-only lines are ignored, as are  lines
              whose first non-whitespace character is a `#'.

       multi-line text
              A  logical  line  starts  with  non-whitespace text. A line that
              starts with whitespace continues a logical line.

<b>TABLE SEARCH ORDER</b>
       With lookups from indexed files such as DB or DBM,  or  from  networked
       tables  such  as  NIS,  LDAP or SQL, patterns are tried in the order as
       listed below:

       <i>user</i>@<i>domain address</i>
              Replace <i>user</i>@<i>domain</i> by <i>address</i>. This form has the highest prece-
              dence.

              This  is  useful  to  clean up addresses produced by legacy mail
              systems.  It can also  be  used  to  produce  <i>Firstname.Lastname</i>
              style addresses, but see below for a simpler solution.

       <i>user address</i>
              Replace  <i>user</i>@<i>site</i>  by  <i>address</i> when <i>site</i> is equal to $<b><a href="postconf.5.html#myorigin">myorigin</a></b>,
              when <i>site</i> is listed in $<b><a href="postconf.5.html#mydestination">mydestination</a></b>, or when it is  listed  in
              $<b><a href="postconf.5.html#inet_interfaces">inet_interfaces</a></b> or $<b><a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a></b>.

              This form is useful for replacing login names by <i>Firstname.Last-</i>
              <i>name</i>.

       @<i>domain address</i>
              Replace other addresses in <i>domain</i> by <i>address</i>.  This form has the
              lowest precedence.

              Note:  @<i>domain</i>  is  a  wild-card.  When  this form is applied to
              recipient addresses, the Postfix SMTP server  accepts  mail  for
              any  recipient  in  <i>domain</i>, regardless of whether that recipient
              exists.  This may turn  your  mail  system  into  a  backscatter
              source:  Postfix  first accepts mail for non-existent recipients
              and then tries to return that mail  as  "undeliverable"  to  the
              often forged sender address.

<b>RESULT ADDRESS REWRITING</b>
       The lookup result is subject to address rewriting:

       <b>o</b>      When  the  result  has the form @<i>otherdomain</i>, the result becomes
              the same <i>user</i> in <i>otherdomain</i>.

       <b>o</b>      When "<b><a href="postconf.5.html#append_at_myorigin">append_at_myorigin</a>=yes</b>", append "<b>@$<a href="postconf.5.html#myorigin">myorigin</a></b>" to  addresses
              without "@domain".

       <b>o</b>      When "<b><a href="postconf.5.html#append_dot_mydomain">append_dot_mydomain</a>=yes</b>", append "<b>.$<a href="postconf.5.html#mydomain">mydomain</a></b>" to addresses
              without ".domain".

<b>ADDRESS EXTENSION</b>
       When a mail address localpart contains the optional recipient delimiter
       (e.g.,  <i>user+foo</i>@<i>domain</i>),  the  lookup  order becomes: <i>user+foo</i>@<i>domain</i>,
       <i>user</i>@<i>domain</i>, <i>user+foo</i>, <i>user</i>, and @<i>domain</i>.

       The  <b><a href="postconf.5.html#propagate_unmatched_extensions">propagate_unmatched_extensions</a></b>  parameter  controls   whether   an
       unmatched address extension (<i>+foo</i>) is propagated to the result of table
       lookup.

<b>REGULAR EXPRESSION TABLES</b>
       This section describes how the table lookups change when the  table  is
       given  in the form of regular expressions. For a description of regular
       expression lookup table syntax, see <a href="regexp_table.5.html"><b>regexp_table</b>(5)</a> or <a href="pcre_table.5.html"><b>pcre_table</b>(5)</a>.

       Each pattern is a regular expression that  is  applied  to  the  entire
       address  being looked up. Thus, <i>user@domain</i> mail addresses are not bro-
       ken up into their <i>user</i> and <i>@domain</i> constituent parts, nor  is  <i>user+foo</i>
       broken up into <i>user</i> and <i>foo</i>.

       Patterns  are  applied  in the order as specified in the table, until a
       pattern is found that matches the search string.

       Results are the same as with indexed file lookups, with the  additional
       feature  that parenthesized substrings from the pattern can be interpo-
       lated as <b>$1</b>, <b>$2</b> and so on.

<b>TCP-BASED TABLES</b>
       This section describes how the table lookups change  when  lookups  are
       directed   to  a  TCP-based  server.  For  a  description  of  the  TCP
       client/server lookup protocol, see <a href="tcp_table.5.html"><b>tcp_table</b>(5)</a>.  This feature  is  not
       available up to and including Postfix version 2.4.

       Each  lookup operation uses the entire address once.  Thus, <i>user@domain</i>
       mail addresses are not broken up  into  their  <i>user</i>  and  <i>@domain</i>  con-
       stituent parts, nor is <i>user+foo</i> broken up into <i>user</i> and <i>foo</i>.

       Results are the same as with indexed file lookups.

<b>BUGS</b>
       The table format does not understand quoting conventions.

<b>CONFIGURATION PARAMETERS</b>
       The  following  <a href="postconf.5.html"><b>main.cf</b></a>  parameters  are especially relevant.  The text
       below provides only a  parameter  summary.  See  <a href="postconf.5.html"><b>postconf</b>(5)</a>  for  more
       details including examples.

       <b><a href="postconf.5.html#canonical_classes">canonical_classes</a></b>
              What addresses are subject to canonical address mapping.

       <b><a href="postconf.5.html#canonical_maps">canonical_maps</a></b>
              List of canonical mapping tables.

       <b><a href="postconf.5.html#recipient_canonical_maps">recipient_canonical_maps</a></b>
              Address  mapping  lookup table for envelope and header recipient
              addresses.

       <b><a href="postconf.5.html#sender_canonical_maps">sender_canonical_maps</a></b>
              Address mapping lookup table  for  envelope  and  header  sender
              addresses.

       <b><a href="postconf.5.html#propagate_unmatched_extensions">propagate_unmatched_extensions</a></b>
              A list of address rewriting or forwarding mechanisms that propa-
              gate an address extension  from  the  original  address  to  the
              result.  Specify zero or more of <b>canonical</b>, <b>virtual</b>, <b>alias</b>, <b>for-</b>
              <b>ward</b>, <b>include</b>, or <b>generic</b>.

       Other parameters of interest:

       <b><a href="postconf.5.html#inet_interfaces">inet_interfaces</a></b>
              The network interface addresses that this system  receives  mail
              on.   You  need  to  stop  and start Postfix when this parameter
              changes.

       <b><a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a></b>
              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_re</a>-
              <a href="postconf.5.html#remote_header_rewrite_domain">write_domain</a> parameter.

       <b><a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a></b>
              Other  interfaces that this machine receives mail on by way of a
              proxy agent or network address translator.

       <b><a href="postconf.5.html#masquerade_classes">masquerade_classes</a></b>
              List of address classes subject to masquerading: zero or more of
              <b>envelope_sender</b>,        <b>envelope_recipient</b>,       <b>header_sender</b>,
              <b>header_recipient</b>.

       <b><a href="postconf.5.html#masquerade_domains">masquerade_domains</a></b>
              List of domains that hide their subdomain structure.

       <b><a href="postconf.5.html#masquerade_exceptions">masquerade_exceptions</a></b>
              List of user names that are not subject to address masquerading.

       <b><a href="postconf.5.html#mydestination">mydestination</a></b>
              List of domains that this mail system considers local.

       <b><a href="postconf.5.html#myorigin">myorigin</a></b>
              The domain that is appended to locally-posted mail.

       <b><a href="postconf.5.html#owner_request_special">owner_request_special</a></b>
              Give special treatment to <b>owner-</b><i>xxx</i> and <i>xxx</i><b>-request</b> addresses.

       <b><a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a></b>
              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.

<b>SEE ALSO</b>
       <a href="cleanup.8.html">cleanup(8)</a>, canonicalize and enqueue mail
       <a href="postmap.1.html">postmap(1)</a>, Postfix lookup table manager
       <a href="postconf.5.html">postconf(5)</a>, configuration parameters
       <a href="virtual.5.html">virtual(5)</a>, virtual aliasing

<b>README FILES</b>
       <a href="DATABASE_README.html">DATABASE_README</a>, Postfix lookup table overview
       <a href="ADDRESS_REWRITING_README.html">ADDRESS_REWRITING_README</a>, address rewriting guide

<b>LICENSE</b>
       The Secure Mailer license must be distributed with this software.

<b>AUTHOR(S)</b>
       Wietse Venema
       IBM T.J. Watson Research
       P.O. Box 704
       Yorktown Heights, NY 10598, USA

       Wietse Venema
       Google, Inc.
       111 8th Avenue
       New York, NY 10011, USA

                                                                  CANONICAL(5)
</pre> </body> </html>