Soluções Anti-Spam

http://www.sonicwall.com/lat/191.html

http://www.ironport.com/technology/ironport_antispam.html

http://www.f-secure.com/small_businesses/products/fsavmse.html

Pelo que me disseram essas sao as 3 melhores solucoes para anti-spam do mercado, o resto é resto..