Sowen, thank's to link for my small contribution to avast4.ini file research
tweakermonkey, probably you will have to add more configurations to your POP3/SMTP settings into your email client.
For instance,
here you have the long history of Walker trying to configure Pegasus Mail. I tried to post there the configuration for Spamihilator. If you need help, let me know. Anyway, I do not use SpamSubtract... If you need help into SpamPal, ask for
Culpeper's help (he is another forum user with a lot of experience).