DomainKeys Identified Mail, or DKIM, is a system for confirming the legitimacy of an email using an electronic signature. When DomainKeys Identified Mail is enabled for a given domain, a public encryption key is published to the global DNS database and a private one is kept on the email server. When a new message is sent, a signature is issued using the private key and when the email message is delivered, the signature is ‘scanned’ by the incoming POP3/IMAP server using the public key. Thus, the receiver can easily distinguish if the message is legitimate or if the sender’s email address has been spoofed. A discrepancy will appear if the content of the email message has been altered in the meantime as well, so DKIM can also be used to ensure that the sent and the delivered emails are identical and that nothing has been attached or erased. This email authentication system will enhance your email security, as you can verify the legitimacy of the important emails that you receive and your associates can do likewise with the messages that you send them. Depending on the given email provider’s policy, a message that fails to pass the test may be erased or may emerge in the recipient’s inbox with a warning alert.
