Wall Street Journal 2/19/04  http://online.wsj.com/article/0,,SB107715143788033447,00.html?mod=technology%5Fcolumns%5Ffeatured%5Flsc

PC Magazine 2/17/04  http://www.pcmag.com/article2/0,4149,1477171,00.asp

PC World 7/28/03  http://www.pcworld.com/resource/printable/article/0,aid,111802,00.asp

USA Today 4/15/03  http://www.usatoday.com/tech/columnist/edwardbaig/2003-04-15-spamblock_x.htm

email.about.com   http://email.about.com/cs/hostingreviews/gr/mailblocks.htm.