Postfix
From Leo's Notes
This page was last edited on 12 February 2019, at 21:54.
Mail Relay
To use Postfix as a mail relay server, edit the /etc/postfix/main.cf configuration with the following:
relayhost = [smtp.example.com]:587
smtp_use_tls = yes
smtp_sasl_auth_enable = no
This assumes that smtp.example.com accepts TLS encrypted SMTP connections via 587.