Barry,
I hope by now you've solved your problem with Pegasus. I just wanted to say that I too used Pegasus, with 5 different e-mail accounts, and did have problems getting all 5 scanned with Avast.
The problem was not with Avast or Pegasus, but my own in-experience and lack of knowledge on configuring e-mail accounts for providers.
I got all of the information I needed through this Forum to get everything running as it should. (I just can't find the posts from over a year ago)
My biggest problem was with the e-mail account through a web site I have.
Prior to Avast my user name was;
myaccountname+mydomain.us
After Avast it had to be;
myaccountname+mydomain.us#mail.mydomain.us
(the ".us" is the type of doman. As in .com , .net , .org , etc)
So, if you haven't already resolved your issue, you're very close.