Viral e-mail - how'd it get past Norton?

I've just recieved an e-mail (a scam) which has not sent itself on to everyone in my address book. Funny thing is, my computer wasn't on when it sent itself. Am I infected with something, or is it nothing to  worry about? The e-mail is reproduced below.

 

Hey
How is going now !
It is amazed.I got a great website,that guys sell electronics,the price is cheapest and quality is nice.Fast service to receive the products from them.
Go and check it :  
MSN:    

 

[edit: Please do not post email addresses per the Participation Guidelines and Terms of Service.]

Message Edited by shannons on 08-29-2009 05:49 PM