alanrf
2
Yes,
the change you made to your AT&T account caused this.
Secure connections cannot be scanned by avast, any other antivirus. That is the whole point of secure connections, they cannot be monitored.
avast does not (and cannot) scan the ports you are now using and cannot insert the “clean” messages. Do not attempt to force avast to do so - you simply will not be able to connect.
There is an alternative however that will allow you to connect securely and still have avast scanning the emails and inserting the “clean” messages.
See this thread:
http://forum.avast.com/index.php?topic=27602.msg238395#msg238395