Thats not entirely true. Ive been getting the same thing emails saying mail I sent was not delivered emails with my email address on them some with other peoples. I have virus protection and do get updates and have never opened an attachment. This virus going around can do this. I believe it is also looking like an undelivered messages so you will click the link and get a virus. my system has been checked and double checked and its virus free but am still getting those emails.