Secure/authenticated email: Checking out Kerberos

TechNewsWorld: "If everyone used secure e-mail with authentication, viruses and worms would not be able to propagate. Spoofing wouldn't work, and phishing expeditions would yield no harvest." Worms might still propogate, but this is a sensible suggestion. I'd love to know how to proceed. Eudora has Kerberos authentication in it, but mine is turned of by default. "Only fill them in if your network administrator tells you to do so." I'll check to see if my ISP, Raw Bandwidth, supports Kerberos authentication, and if so, what that really means.