Hi all

Im trying to troubleshoot a odd SMTP bug at work, and so far no one has been able to help me figure it out, so moving across the few forums I use looking for that magic bit of advise

The short version is:

Two exchange servers, different sites, same WAN, setup in a DAG group

As far as I can see both servers are setup exactly the same, same version numbers, same configs, etc
When sending a test email to server 1, I can see both on my test application (SMTP Diag Tool), and on the exchange logs, the SMTP process working, and then I get the test email in my inbox
When sending to server 2, I can see the logs working, but then it fails
The server shows "Receving message with InternetMessageID" and then nothing else on those logs
On the test software, I can see Connection closed error, 
Same test with telnet and get a Connection to host lost error on server 2

Iv tried searching every log file I can find, and all over the internet, but so far nothing seems to tell me why server 2 fails and server 1 works fine

Im sure im missing something somewhere, but no idea what?

Any ideas or help please?