This has been floating around since last November and the Mail Server Report portion has been around even longer (Oct. 2006.) I really don't think that this is too much of a concern at this time since AV software has been updated to blunt this particular threat. I think the biggest now is malware being transmitted via social media, ie. Facebook, Twitter, Skype, etc...

Fred's post does serve to remind us that we should practice good e-mail safety when we are using it. Here is a link to some info on e-mail safety:

http://www.wiredsafety.org/safety/email_safety/index.html

Cheers!
Bill