What Richard was saying is that you/yourPC played no part in the sending of these e-mails. It was simply your address that was used to make it look as though you were responsible.
Mistress Fob's address was used (just the one time) to send a SoBig infected e-mail to the Hilton Hotels Group. Needless to say, the Hilton's automatic filtering process caught it and send her a notification to that effect.
All automatic. I doubt that anyone/thing with warm blood knew anything about it.