Postfix - Using a Smarthost to relay email

Configuring PostFix to use a Smarthost

Routing all mails to a smarthost :

These instructions assume the postfixconfig files live in /etc/postfix/main.cf

In /etc/postfix/main.cfadd the line:

relayhost = mailout.serverpronto.com

Routing all mails for a specific domain to a smarthost :

Add a line to /etc/postfix/transport:

example.com smtp:mailout.serverpronto.com

generate a postmap file :

postmap hash:/etc/postfix/transport

To use the transport file, add or edit a line in /etc/postfix/main.cf:

transport_maps = hash:/etc/postfix/transport

Restart Postfix and all mail. The mail for selected domains should go trough the Smarthost.

Information originally posted at http://help.comodo.com/topic-157-1-288-4540-.html