I have an Exchange 2010 mail server. It has been working for a couple of years. 3 days ago it stopped receiving mail. I can send between internal users, and send internally/externally, but not receive from externally.
I have rebooted the server, done updates.
I can telnet to port 25 from inside my network to the server and get a valid response.
I can't telnet to port 25 from outside the network.
I have removed port forwarding rules from the router and added port 25 again.
I have done tests externally to see that port 25 is open inbound to my network.
When I send messages into the network, they expire with: #550 4.4.7 QUEUE.Expired; message expired ##.
The only problem experienced is the domain can't receive external mail, outlook, calenders, internal mail, outbound mail works.
Thanks in advance,