Postfix: The Definitive Guide

master.cf

The Postfix master daemon launches all of the other Postfix services as they are needed. The various services, and how they are run, are specified in the master.cf file.

The master configuration file works like other Postfix configuration files. A comment is marked by a # character at the beginning of a line. Comments and blank lines are ignored. Long lines can continue onto subsequent lines by starting the carry-over lines with whitespace.

Example 4-2 shows a sample file. Each column contains a specific configuration option. A dash in a column indicates the default setting for that column. Some default values come from parameters in the main.cf file.

Example 4-2. Sample master.cf file

#= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = # service type private unpriv chroot wakeup maxproc command + args # name (yes) (yes) (yes) (never) (100) #= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = smtp inet n - y - - smtpd pickup fifo n - n 60 1 pickup cleanup unix n - n - 0 cleanup qmgr fifo n - n 300 1 qmgr rewrite unix - - n - - trivial-rewrite bounce unix - - n - 0 bounce defer unix - - n - 0 bounce flush unix n - n 1000? 0 flush proxymap unix - - n - - proxymap smtp unix - - y - - smtp relay unix - - y - - smtp -o smtp_helo_timeout=5 -o smtp_connect_timeout=5 showq unix n - n - - showq error unix - - n - - error local unix - n n - - local virtual unix - n n - - virtual lmtp unix - - n - - lmtp maildrop unix - n n - - pipe flags=DRhu user=vmail argv=/usr/local/bin/maildrop ...