DomainKeys Identified Mail, or DKIM, is a method for checking the authenticity of an email using an e-signature. When DKIM is enabled for a given domain, a public encryption key is published to the global DNS system and a private one is stored on the mail server. If a new email is sent, a signature is issued using the private key and when the email is received, the signature is validated by the incoming server using the public key. Thus, the receiver can easily recognize if the email message is legitimate or if the sender’s email address has been forged. A mismatch will appear if the content of the email message has been modified on its way as well, so DKIM can also be used to make sure that the sent and the delivered email messages are identical and that nothing has been attached or deleted. This authentication system will enhance your email security, since you can validate the legitimacy of the important email messages that you receive and your partners can do the same with the email messages that you send them. Depending on the particular mail service provider’s adopted policy, a message that fails to pass the check may be deleted or may appear in the receiver’s mailbox with a warning symbol.