The DKIM and DomainKey specifications provide methods for domain level authentication of email messages. They can help in reducing the amount of UCE (Unsolicted Commercial Email), AKA spam, recieved by users of electronic mail. I was unable to find a Java implementation of DKIM, so I decided I would write one....
JavaDKIM is born!
Update: 2009-06-07 Java DKIM 1.0 has been released!