This weekend we moved our mail server. After many troubles with copying we managed to get it running on the new host (ESXi5.5).
For the mail server we opened ports 80, 443, 135 and 25. All dns records point to the new IP. I also recreated the recursive lookup zone for the new internal ip.
Yet, mail flow is not working while I can connect and login on owa and connect with Outlook from both inside and outside the network. Internal mail, even from and to the same address is not working.
This is the first time we moved a mail server and we might have missed something. Any ideas where to look?