Using Microsoft Excange 2003 SP2.
Have just got a load of NDR's - which resulted in getting the IP getting RFC-IGNORANT and having to move the mail server to a different IP address so that mails would be allowed to be sent to destination domain.
Origianlly to stop the large amounts of NDR's being produced by some suspicious and un-know source, within Global Settings on the Exchange Server I set the following :-
Under tab for "Recipient Filtering".
I checked the box for "filter recipients that are not in the directory".
SenderID Filtering Tab - set to "Delete (the message will be accepted and then deleted ;no NDR will be sent back to the sender)
We seemed to get to the point that outgoing mails sat in the QUEUE's and after some investigation it seems we were on an RFC-IGNORANT black list based on the IP address. We moved the IP address and the mail queued up were then sent.
Are the steps above enough to minimise this issue ? How do we get off this black list for the IP ?