On Wed, 23 Apr 2014, James B. Byrne wrote:
Does the idea of configuring Postfix so that external (to our network) smtp connections are only accepted from servers identified with MX records for the connecting IP address make any sense? Is it possible?
No, it makes no sense at all. MX records define what hosts RECEIVE mail for a domain. They say nothing about what hosts should be SENDING mail for a domain. Many large ISPs use separate systems for receiving and sending mail. What you want to do will reject large quantities of legitimate mail.
-- Larry Stone lston...@stonejongleux.com