I have one server A that is configured as example DOT com machine with postfix installed on it that is also configured with $myhostname example DOT com . Server A has an static IP.

In addition, DNS is registered to another server B which hosts our website.

Our MX records points to third server C.

if I want to send mail with recipient office AT example DOT com from server A (let's say PHP script running on server A) it will use local postfix deamon and postfix will deliver mail locally for user office on server A (since server A is configured with example DOT com ). It will not use global MX record for example DOT com and forward mail to SMTP deamon on server C.

What is solution to insist on postfix accessing global DNS MX record for example DOT com (server C) and not just delivering mail on local server A since it sees it as example DOT com as well?

Sasha Rudan