For some reason, if I have my WindowsCE or PocketPC connected to my desktop where I am running Avast Home, the PocketPC tries to check email via ActiveSync. Avast opens the connection on port 110 to my ISP but then hangs. The only workaround I have is removing the “Internet Mail” service of Avast. Has anyone else seen this problem and if so, do you have a workaround? 
Someone else is having a simulair problem. There is another thread which tells more. Can’t recall exactly what is said there. Please use the search function to find it.
If I remember correctly it has to do with something like the driver(s) for the external device.
Maybe in this board there is the solution: http://forum.avast.com/index.php?board=7
Anyway, which port does ActiveSync listen to get (download) email?
Its not Activesync. Its the PocketPC doing a regular POP3 call on port 110. Avast typically listens on this port to make sure there is no virus coming in. But it never completes the call.