The SMTP banner on our Exchange 2013 server does not appear when we connect via telnet on port 25.
When we run telnet locally on the Exchange 2013 server we receive the SMTP banner. Telnet to Exchange 2013 from another server in the same subnet will connect but we only receive a blank screen, no SMTP banner. If we run telnet on port 2525 from another server
in the same subnet we do see the SMTP banner.
The Windows host firewall on Exchange 2013 server is disabled. No AV is installed on the server.
We have restarted Exchange services and even restarted Exchange 2013 server. We are running Exchange 2013 CU1 on Windows 2008 R2. We have both Exchange roles installed on the server. This is a new setup.
Any suggestions?