Most AV pgms. have a e-mail filter as part of its defense, check to see if yours does this. Also, its been my experience that some e-mail services those that provide thier own email like Yahoo, Excite, JUno, etc. will have a similar defense on thier part but also you add to it by placing emails to it that appear to be spam or junk mail as well as tweaking how that service acts. The trick is, don't open any emails that you don't know of the sender or those repeated from a similar source. Also, since it appears that IE and Outlook are prone to weakness of thier own, maybe another browser is in order.
I use to use a pgm. called: Mail Washer(freeware). It was a great helper. You could further its use but adding and tweaking its defense those you found offensive. You could friends to a known list to get thier emails and others be trashed or at least look at email headers and see what needn't be opened.