Can you try this:

  • Create a backup of Avast4.ini

  • Than change the mail section part in avast4.ini so that these settings are there:
    [MailScanner]
    Log=20
    DefaultPopServer=
    DefaultSmtpServer=
    ShowTrayIcon=1
    UseDefaultSmtp=0
    AutoSetProtection=0
    PopListen=
    SmtpListen=
    ImapListen=

  • Setup the mail as if Avast isn’t there.

  • Check if the mail is working

Let us know if it helps.