Singed/Encrypted email?

rbannon writes: The O'Reilly's website published an article by François Joseph de Kermadec on "How to Set Up Encrypted Mail on Mac OS X" almost three years ago (01/20/2004), but I've noticed that this technology has not taken hold. On Mac OS X it is incredible transparent to use S/MIME security and encryption, and thawte(TM) provides free certificates with an extensive network of notaries to validate authenticity. Why are so few using this technology? I've also noticed that many PC users are frightened when they get an email from me, because they think the certificate has malicious intentions.