Slinger,
It very rarely happens that anyone has to give up, so I was wondering:-
Are you running through a proxy.
Do you have proxy checked in your connection settings.
Are you connecting through a router and/or hardware firewall.
Are you on/connecting through a network.
Are you installing the latest version of Avast (4.5.561)
Are there any other symptoms apart from no e-mail and no Avast updates.
btw: how do you connect to the internet.. dial-up, broadband.
Sorry if I missed anything in you posts, but looking for things to give a clue to the problem.