I have recently migrated from Exchange 2003 to Exchange 2010. Several times a day, I get alarms for imaps and pop3s, which are resolved less than a minute later.
The graph (http://www.elyograg.org/pop3s.png) shows hourly spikes in
reponse time. The alarms are not every hour, but when they do happen,
they correspond to the spikes. The email from xymon looks like this.
Note the "seconds" value, which is extremely low. Anytime there's an
alarm, the value is low like this.
Service pop3s on server.example.com is not OK : Service unavailable (connect timeout)
Seconds: 0.003435
There have been no complaints from people who use the service, and believe me, I'd hear about it if there was a problem.
The non-SSL versions are not alarming. I just noticed that the graph for pop3 has two entries - pop3 and pop3s. From what I can tell, it checks TLS on the standard test. The pop3s graph on the pop3 entry looks identical to the pop3s graph I've included here, except it's red instead of blue.
I suspect that it's related to the throttling policies in Exchange 2010, but I don't know what to change. I don't want to open the default throttling policy way up, but I did change the anonymous connection limit from 1 to 5. Has anyone else had this problem and found a way to solve it?
Thanks, Shawn