/var/lib/qmail/queue/local/ is in qmail 1.06-5.
This file is owned by qmails:qmail, with mode 0o700.
..
/var/lib/qmail/queue/local/0/
/var/lib/qmail/queue/local/1/
/var/lib/qmail/queue/local/10/
/var/lib/qmail/queue/local/11/
/var/lib/qmail/queue/local/12/
/var/lib/qmail/queue/local/13/
/var/lib/qmail/queue/local/14/
/var/lib/qmail/queue/local/15/
/var/lib/qmail/queue/local/16/
/var/lib/qmail/queue/local/17/
/var/lib/qmail/queue/local/18/
/var/lib/qmail/queue/local/19/
/var/lib/qmail/queue/local/2/
/var/lib/qmail/queue/local/20/
/var/lib/qmail/queue/local/21/
/var/lib/qmail/queue/local/22/
/var/lib/qmail/queue/local/3/
/var/lib/qmail/queue/local/4/
/var/lib/qmail/queue/local/5/
/var/lib/qmail/queue/local/6/
/var/lib/qmail/queue/local/7/
/var/lib/qmail/queue/local/8/
/var/lib/qmail/queue/local/9/