DomainKeys Identified Mail, or DKIM, is a method for verifying the authenticity of an email using a digital signature. When DomainKeys Identified Mail is activated for a given domain name, a public key is published to the global DNS system and a private one is kept on the mail server. If a new message is sent, a signature is issued using the private key and when the email message is received, that signature is checked by the incoming POP3/IMAP mail server using the public key. In this way, the recipient can easily know if the email message is genuine or if the sender’s address has been forged. A mismatch will appear if the content of the email message has been edited in the meantime as well, so DomainKeys Identified Mail can also be used to ensure that the sent and the delivered emails are identical and that nothing has been added or deleted. This email authentication system will enhance your email security, since you can validate the genuineness of the important email messages that you get and your associates can do likewise with the email messages that you send them. Depending on the given mail service provider’s policy, a message that fails the test may be deleted or may appear in the recipient’s inbox with a warning.