Postfix mailer configuration

Postfix mailer configuration
__   _
  -o)/ /  (_)__  __ ____  __      Derek Winterstien
  /\\ /__/ / _ \/ // /\ \/ /      r.o.a.c.h.@.r.o.b.o.t.z...c.o.m
 _\_v __/_/_//_/\_,_/ /_/\_\      Trustix Secure Linux
..............................................................................

Postfix should be configured to start up on boot

  chkconfig Postfix on

Make some configuration changes in postfix

  vi /etc/postfix/main.cf

Add / Modify the following

inet_interfaces = all
mydestination = $myhostname, localhost.$mydomain, $mydomain
myorigin = $mydomain

Logs: (var/log/mail)

 debug
 errors
 info - mail delivery attempts
 notice
 warnings - such as hostname verification

Hosting Domains


  1. . canonical hostname and/or domain of machine
  2. . virtual alias domain virtual domain uses unix passwd system accounts
  3. . virtual mailbox domain virtual domain and independent accounts

Configuration: mailbox format


Choose a mailbox format. This guide will cover mbox as opposed to MailDir.

#!!  home_mailbox = Mailbox <- delete or remark out this line.  Do not specify
     the home_mailbox parameter for mbox style delivery.

  mail_spool_directory = /var/spool/mail

Configuration: main.cf


Edit main.cf

  myorigin

  mydestination

  mynetworks_style     ignord if mynetworks list specified

  mynetworks           you can specify a plain text file to contain valid

Example a10: mynetworks


You can list the relays in the main.cf file:

 mynetworks = 168.100.189.0/28, 127.0.0.0/8

Or refer to a hash file:

 mynetworks = hash:/etc/postfix/relay_table

Or a flat text file:

 mynetworks = /etc/postfix/relay_table

In the flat text file, # comments a line, an IP specifies a single host allowed relay. The sendmail format of a partial IP, X.X.X does NOT work. To specify a network use network metrics X.X.X.X/24

Example a20: virtual_alias_maps


You can specify a hash table file for virtual_alias_maps, which is simular to sendmail's 'virtusertable' file with one important difference: postfix virtual domains do not automatically map to unix system accounts.

  • Specify in main.cf:
 virtual_alias_maps = hash:/etc/postfix/virtusers
  • Format:
 username@virtualdomain.com	unixmailbox
  • Hash it:
 postmap virtusers
  • Explained:
The addess username@virtualdomain.com will be directed to the unix system

mailbox named unixmailbox.

Postfix Lookup Table Types: type:name


Not all of them, but on Linux here are a few important ones...

regexp regular expressions lookup table
hash   standard hash index file
sdbm   sdbm supported hash index file
pcre   perl style regular expressions table

Virtual Mailbox Domains and Non-UNIX Accounts


You must use a pop or imap server that is compatible with every recipient address having its own virtual mailbox. For example, popa3d is a great pop server known for simplicity and security, but it will not recognize your virtual, non system mailboxes.

Graylisting and spamd


Visit these updated and related pages

Last modified on 13 February 2014, at 20:35