How would you go about locking down Postfix after following the lastest how-to 1. What I have is an other server that is the MX for my domains that already does AntiVirus, AntiSpam and Content filtering. How would I go about locking down the Postfix to only accept email from my SMTP-Authenticated users and the upstream filter server? That way "people with too much free time" could not bypass DNS MX records and send directly to my new beautiful server. Thanks in advance
Set Code: mynetworks = 127.0.0.0/8 1.2.3.4/32 in /etc/postfix/main.cf and restart Postfix. 1.2.3.4 is the IP address of your upstream filter server.
