Hello everyone!
I have a server that is running MS Windows Server 2012R2 and MS Exchange 2013 only CAS role. During last couple of weeks I have my server failed to receive a messages from outside.
When I'm trying to telnet on ipv6 port 25, I get normal answer
220 ex2013cas01.example.net Microsoft ESMTP MAIL Service ready at Sun, 4 Jan 2015 00:05:52 +0300
But if I telnet on ipv4 port 25, I get connection refused message.
To get SMTP works again I need to restart MSExchangeFrontEndTransport service. Even after an update to CU7 problem is still exist.
Is there any way to solve that?