Thanks for the information. I’ve had this problem for 2 years. Everyday I have to delete upto 2k of messages. 75% are junk spam and others are the standard [Mail Delivery Subsystem with the subject as Returned mail: see transcript for details].
Yesterday Windows Live Messenger would popup with a link attached to a porn titled file and had my first name as the contact name. I tried to block the sender three times, but I continued to receive more pop-ups hourly so I closed the application. After a system check I noticed a windows upgrade that was almost 200 MB and took several hours to update that caused me some concern, but it was legit.
Just to be sure I immediatly called my host to backup my portals and forum as well as change all passwords.