I have recently taken on a local gym as a client that has their own Exchange Server. Recently all ATT email addresses have started to kick back as being blocked. The ISp is ATT.
They have a static IP range, and the gateway IP. If you ping the mail.domainname , it resolves back to the gateway IP, which is *.*.*.110.
When I called ATT to find out what the issue was, they stated that the gateway IP cannot be used for mail, and that we have to use one out of the blocks of statics. .5 through .9.
This is where I am confused. How do I change the exchange server to use a different IP than what is on the NIC, and is what the tech told me even correct?
I mean this used to work with no issue and now it doesn't. We have no problems sending mail to any other set of addresses.
They also said I would have to submit a reverse DNS request to enable the IP to resolve to the mail. address.
I am completely lost on this one.