I too am having issues with Avast Notifications on EVERY site I have deployed in the past 3 weeks - around 12 sites.
The issue seems to relate to the UTF-Encoded Subject line from the Avast Clients … Any help would be appreciated…
here is the pattern so far :-
Avast Client sends local notify to local site Exchange 2003 server that has the Avast Exchange and SMTP connectors installed.
Exchange2003 CANNOT send to/via mail.bigpond.com - keeps getting timeout - Bigpond Support are hopeless to try and get past a silly level 1 tech telling you to restart your DSL modem
Exchange2003 CANNOT send to/via cisco ironport devices - keeps getting timeout - Cisco/Ironport have a case open here and are basically ignoring the case as they likely have no clue and I suspect it has become too hard for them - they have complete SMTP transaction dumps.
Exchange2003 CAN send to another Exchange 2003 server direct (I have used custom SMTP connectors on EACH and EVERY site to work-around this for now)
Any help would be appreciated - I am not completely sure if this is related but it seems suspiciously similar…