Some people on my Outlook address book are getting emails with my address in the From box, advertising Viagra, etc. Each time the link in the email is different. Of course, I've never sent these, so it must be some sort of malware. I run a virus and spyware scan daily, along with Spybot weekly, but nothing has been detected.
Where else can I look for the source of these emails? Any suggestions would be greatly appreciated . . .