Replace Outlook with a real emailer like Eudora - problem solved!
Or run under Linux instead of the swiss cheese that the folks at Redmond call an operating system.
People seem to want things that are feature-rich so that lots of thing happen automagically, but then blame the maker for their own inability to get it to work safely.
It is so tiresome to hear people (who interestingly enough claim to not use the product) bellyache about that product as if they have some sort of moral high ground. Virus writers will exploit that which is popular because that is how they can get the widest effect. If some other product were the most popular, then that is what they would target.
If you foolishly believe that some simple little pop3 mailer or your Macintosh has no vulnerabilities... then you are gravely mistaken. People don't write many viruses for Amiga either.