I think Dusty may have posted this before for a problem he had with a yahoo MTA, but it's worth repeating.
An IMGate user in Bolivia had a problem with an MS ip that sent EHLO delivery.pens.microsoft.com It was rejected "cannot find your hostname" because in from_senders_bogus: microsoft.com reject_unknown_client The sending ip didn't have a PTR record. He didn't want to take top-level microsoft.com out of from_senders_bogus.map, so he put this in his IMGate hosts file: 207.46.248.66 delivery.pens.microsoft.com ... because he had to have SOMETHING as a hostname, and didn't want to use top-level domain of microsoft.com, which would defeat the purpose of having microsoft.com in from_senders_bogus. And now IMGates' reject_unknown_client PTR + A query succeeds from IMGate's hosts file rather than failing in DNS. mui cool, signor Justiniano :)) note your hosts file can have: 207.46.248.66 any.damn.thing.you.can.dream.up and it would work, because the A record and the PTR record "match". :)) this Len
