I have Windows 2008 R2 with AD and Exchange 2013(10.0.2.2). And I'm using Postfix as SMTP for incoming/outgoing emails, which has two Ethernet interfaces - External IP and Local IP(10.0.2.25). I have added this SMTP as send connector for all the emails (*) and as receive connector for my domain. And this send connector is only one, set as Smart Host.
However when I send email from Outlook, nothing is happening. Postfix is not receiving from Exchange anything nothing is being logged out. Incoming emails are arriving through the same Postfix with no issues
Exchange2013(10.0.2.2) <== OK ==< (10.0.2.25) Postfix (Ext IP) <== Internet
Exchange2013(10.0.2.2) >== X?? ==> (10.0.2.25) Postfix
How do I debug Exchange in this case? I've seen on some forums someone mentioned about expired certificates on Exchange. Ping and telnet to 10.0.2.25 25
is all good
Solved the issue is restarting the transport service
It took quite long to restart, but now emails arrive to Postfix
So glad to know this issue is resolved. Sometimes, restart all services or server will solves many issues. You could mark the reply as answer.