Well I have never seen multiple warnings, I thought that avast served up one and you have to select an action first before another would be displayed.
What does the Subject say, I'm assuming it is blank ?
This is part Of the Internet Mail (which includes NNTP coverage), Heuristics, and you can lower the Heuristic Level to Medium or Low so that it doesn't trap the suspicious subject. You could also set it to Custom and that would activate the Customize button and also allow you to do a more detailed customization. I also suggest you browse the avast help file, Resident Scanners, Internet Mail Provider Settings, Heuristics page and the Heuristics Advanced page for more detailed information.
