Postfix Configuration

Postfix must be configured as a mail relay (smarthost gateway). Its purpose is to:

  • Accept unencrypted SMTP connections (no TLS, no AUTH) from trusted internal devices.

  • Forward all outgoing mail to an external SMTP relay.

  • Enforce TLS encryption for outbound delivery.

  • Operate using an IP-based trust model (without SMTP authentication).

Core Configuration Concepts

If parameters are not explicitly mentioned, they remain unchanged from the default configuration.

The configuration file is usually located at:

/etc/postfix/main.cf

If you cannot find the configuration file, the following command displays the location of the file:

# postconf config_directory

To display only active Postfix configuration parameters:

# postconf -n