postfix

Check configuration

$ sudo postfix check

$ sudo postfix status

$ sudo postfix start

$ sudo postfix stop

$ sudo postfix flush

$ sudo postfix reload

postfix [-c configdir] [**-D**] command_

postfix is the control program for the Postfix mail transfer agent. It manages starting, stopping, and reconfiguring the mail system components.
Postfix is designed for security and performance, running multiple separate processes with minimal privileges. The control program coordinates these processes.

-c _config_dir_

Alternate configuration directory

Debug mode

/etc/postfix/main.cf

Primary configuration file defining hostname, domain, relay settings, network restrictions, TLS, and all major Postfix parameters.

Defines Postfix service components (smtpd, cleanup, local, etc.) and their process limits, chroot settings, and command-line options.

Virtual alias mapping for email address rewriting. Requires postmap to rebuild the database after changes.

Controls mail routing by destination domain. Requires postmap after editing.

check

Verify configuration for errors

Start the Postfix mail system

Stop the Postfix mail system

Stop immediately without finishing deliveries

Force delivery of queued mail

Reload configuration without restart

Check if Postfix is running

Requires root privileges for most commands. Mail queue persists across restarts. Check configuration before reload. Abort may lose mail in transit.

Postfix was written by Wietse Venema at IBM Research as a secure, fast replacement for Sendmail. Released in 1998, it became one of the most popular MTAs due to its security design and ease of configuration.

postconf(1), postqueue(1), sendmail(8)