We host our email on an internal server. Recently we have started getting bouce backs from various other servers. Most seem to have the following error:
Reason: Remote SMTP Server Returned: 550 Sender IP reverse lookup rejected
I have checked all the blacklists and we don't seem to be listed on any. I have done a reverse lookup from several sites and they all seem to be responding with the correct rDNS of the mailserver.
Does anyone have any suggestions?