DomainKeys Identified Mail, or DKIM, is a system for confirming the authenticity of an email by using an e-signature. When DomainKeys Identified Mail is enabled for a specific domain name, a public cryptographic key is published to the global DNS database and a private one is stored on the mail server. When a new email is sent, a signature is generated using the private key and when the message is received, that signature is ‘scanned’ by the incoming POP3/IMAP email server using the public key. Thus, the recipient can easily tell if the message is legitimate or if the sender’s address has been forged. A mismatch will appear if the content of the email message has been altered on its way as well, so DomainKeys Identified Mail 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 heighten your email security, since you can verify the genuineness of the important emails that you get and your associates can do the same with the emails that you send them. Based on the given mail service provider’s policies, an email message that fails the check may be erased or may appear in the receiver’s inbox with a warning sign.
