On Mon, 5 Apr 2004, Arnold Nipper wrote:
Today I run across a MTA which refused to accept mail because it could not detect an MX record for the reverse mapping of the IP address of the server which tried to deliver mail. Is this correct?
Not if you want to get mail, no. :)
Or: if A is the IP Address of server trying to deliver mail, does mx(reverse(A)) have to exist?
This is yet another misguided effort to semi-telepathically tell if a sender is "suspicious". Personally, I see nothing odd about a largish operation having one set of servers accepting mail and another set exclusively acting as smtp relays for customer mail. People that choose to do the "does it have an mx check" are hopefully blocking some really large amount of legit mail with the spam, as I can think of dozens of reasons why someone might wish to have their inbound mxers seperate from their outbound relays... Charles
-- Arnold