Setting up Postfix with use with freerelay

Edit /etc/postfix/main.cf and add the following lines: smtp_use_tls = yes smtp_tls_key_file = /etc/postfix/certs/minfine.key smtp_tls_cert_file = /etc/postfix/certs/minfine.crt smtp_tls_CAfile = /etc/postfix/certs/freerelayCA2.crt.crt relayhost = [freerelay.err.no]:2525 After doing that, restart postfix and check that relaying works. Freerelay listens to port 25, 587 (submission), 6667 (irc) and 2525, so if any of those are blocked in your network, try another one.