When using DomainKeys, your domain can publish policy statements that can help receivers make choices about the mail they receive from your domain. The DomainKeys -01 specification defines three policies: the amount of mail signed using DomainKeys (some or all), the testing status of the domain, and a reporting address. If a domain is in testing mode, the receiver should not treat unsigned or unverifiable email
differently from verified email. However, if a domain is not in testing mode and claims to sign all mail, a receiver should treat unsigned mail harshly, as the sender is claiming that the mail is a forgery.
The tool below allows the mail adminstrator to test a domain their domain to determine if the DNS entry is valid, and to determine what policies are in existance.