Setup the mail as if Avast isn't there and check if it is working.
Before I posted to this forum, I unistalled Avast, and then deleted my outlook account, I recreated. Everything was fine, could send and receive emails. I then installed latest Avast and again I experienced problems with sending mail. If I 'terminate' the 'Internet Mail' provider then I can send emails. The 'Outlook/Exchange' provider doesn't make a difference if I terminate or not.
Also make sure it is not your firewall who is blocking things.
I disabled the firewall and still couldn't send emails.
And check the settings in avast4.ini under the [mailscanner] section.
my avast4.ini doesn't have this [mailscanner] section. Could that be the problem? What should this section have? Also has anyone got mail working with Outlook 2000 (I wonder because I guess most people will have 2002 or 2003)