After having a problem with spammers spoofing my work email address, I came across some info on DomainKeys (which use public and private keys to verify the origin of emails). Sounds like a good idea, specially since emails are so stunningly easy to spoof. What are your thoughts? Ever used them before?
(handy link)
http://antispam.yahoo.com/domainkeys
(handy link)
http://antispam.yahoo.com/domainkeys