[Ti] Off_Topic: Are there OSX viruses?

[Tarik Bilgin]

What's happening here most likely is that some infected computer 
(windows) with some sort of worm/trojan with an SMTP engine and where  
your email address is  in their outlook address is sending SPAM using a 
spoofed "from" address (trivial to do) to a mail domain with SPAM 
filtering.

The mail domain is then bouncing that email back to the from address 
(your address)

If you get a lot of these most likely a close friend or business 
contact has a worm on their computer.

--
Tarik