I have spent many a lunch hour (when AWAD was slow) looking through the Urban Legends Reference Pages. You can find that email (or a close relative) there:

http://www.snopes.com/language/document/1872rule.htm

Once you've surfed that site a bit, you realize there's no point in believing much of what comes in your inbox. Anyway, Barbara Mikkelson, who writes most of the articles there, always has interesting analyses of why particular bits of urban lore are so well-loved. This one falls into the "Aren't we feeling smug at how far we've come" category, according to her analysis.