Ok, well email clients can't use SSL with Avast, since it would block Avast from scanning the messages.
From what I've read, you have to setup your email client as a normal POP account, without SSL. Avast will secure the connection for you.
The Avast4.ini file where you could change the maximum amount of connections was usually located here: "C:\Program Files\Alwil Software\Avast4\DATA\avast4.ini".
I don't have a clue where it is in version 5 or 6 though, I don't have that on my systems here. Maybe someone else can chime in.