I came across an unusual one today whereby one of the Exchange 2013 servers for a client had stopped accepting POP3 connections. If you were to telnet to the server on port 110 you would just get a blank connection and if you type anything it would end the connection. I’ve seen things like this in the past because of firewalls etc. and so began looking in that direction but alas after exploring every other avenue the problem was that managed availability has set the PopProxy component to Inactive.
I only found this out after turning up the diagnostic logging for the Pop3 services which I did using these commands
Set-EventLogLevel -Identity “MSExchange POP3 BE\General” -Level High
Set-EventLogLevel -Identity “MSExchange POP3\General” -Level High
After I restarted the POP3 services I then noticed this in the event log:
Event Log: Application
Event ID: 1011
Details: The POP3 server’s Online status has changed to false.
I then ran this command Get-ServerComponentState -Identity SERVERNAME and sure enough it showed that the PopProxy component was Inactive. To get back to Active I then then ran this command:
Set-ServerComponentState -Identity SERVERNAME -Component PopProxy
Re-running the Get-ServerComponentState command shows that it was back to being Active again. Now comes the task of trawling through the Managed Availability logs to find when and why it thought it needed to put the PopProxy component into an Inactive state.
Perhaps this will remind to start looking at Managed Availability sooner in my troubleshooting process rather than it being the last thing I think of to check. I did come across this whilst troubleshooting which looks good but I haven’t tested it https://managedavailabilitytroubleshooter.codeplex.com/
Don’t forget to also set your diagnostic logging back down again afterwards with these commands:
Set-EventLogLevel -Identity “MSExchange POP3 BE\General” -Level Lowest
Set-EventLogLevel -Identity “MSExchange POP3\General” -Level Lowest