DomainKeys Identified Mail, or DKIM, is a method for verifying the authenticity of an email by using an e-signature. When DomainKeys Identified Mail is enabled for a given domain name, a public encryption key is published to the global DNS database and a private one is kept on the email server. When a new email is sent, a signature is generated using the private key and when the email message is delivered, that signature is checked by the POP3/IMAP mail server using the public key. In this way, the receiver can easily tell if the message is legitimate or if the sender’s address has been forged. A mismatch will occur if the content of the email message has been altered on its way as well, so DKIM can also be used to ensure that the sent and the delivered messages are identical and that nothing has been added or erased. This email authentication system will heighten your email security, since you can verify the legitimacy of the important email messages that you get and your associates can do the same with the email messages that you send them. Depending on the particular email service provider’s policies, an email message that fails the examination may be removed or may reach the recipient’s inbox with a warning notification.
