...hit their targets, and sender authentication makes it harder for them to break through the system. Most anti-spamproducts filter e-mails based on content, but the best way to protect your e-mail is on the address of the sender and recipient...
http://www.computerweekly.com/Articles/2004/10/20/206125/your-shout.htm
...Anti-Spam 3.0 Performs Best Among Leading Anti-spamProducts, Wins Top Award From Virus Bulletin VB Spam Award...sound methodology and reproduce the quality of anti-spamproducts the way they actually perform on end users’ computers...
http://www.kaspersky.com/news?id=207575856