I see your problem right away. You're using Outlook.
Those scr viruses are Klem32 email worms, so it's probably impossible at this point to know who originated the one you're talking about.
I get about 40 Klem32 worms (or dirivitives thereof) every week. My Norton picks 'em up on the way in so I don't even have to think about it very much. And I get too many to follow up on too, so I just get rid of the emails and carry on with my day.
By the way.... switch to Eudora 5.1
The vast majority of those email viruses are created with Outlook and Outlook Express in mind. However Eudora just doesn't understand what to do with email viruses and worms.