Yahoo have taken another leap to fight email scammers using DomainKeys Identified Mail or (DKIM) which was approved by Internet Engineering Task Force (IETF) More information can be found on this blog
http://yodel.yahoo.com/2007/05/22/one-small-step-for-email-one-giant-leap-for-internet-safety/

Some excerpt:

DKIM is an email authentication framework that addresses the widespread issue of email forgery, using cryptography to verify the domain of the sender. It allows email providers to validate an email’s originating domain, making use of blacklists and whitelists more effective. It also makes phishing attacks easier to detect by helping to identify abusive domains.

This is good to know since we are already fed up with those phishing emails, scammers or spoofers trying to rob usand even infect or personal computers using their malicious codes attached to the emails. Great start and big impact the email industry.