PhishTank is a free community site where anyone can submit, verify, track and share phishing data. PhishTank is operated by OpenDNS (see how to improve your local ISP DNS performance /speed with OpenDNS which offers free DNS servers that will automatically block phishing sites. It works transparently with any operating system and any web browse).
Phishing is a fraudulent attempt, usually made through email, to steal your personal information. Generally, people who reads site such as Digg or Slashdot everyday, are aware of phishing (see wikipedia article for more info).
PhishTank is free to everyone, both the website and the data via the API. So you can verify the integrity of an email.
From the site:
PhishTank is not protection. PhishTank is an information clearinghouse, which helps to pour sunshine on some of the dark alleys of the Internet. PhishTank provides accurate, actionable information to anyone trying to identify bad actors, whether for themselves or for others (i.e., building security tools). Read the complete FAQ about this project here OR Join the fight against phishing :)