DomainKeys Identified Mail, or DKIM, is a method for validating the genuineness of an email message by using an e-signature. When DKIM is activated for a specific domain name, a public encryption key is published to the global DNS database and a private one is kept on the mail server. If a new message is sent, a signature is generated using the private key and when the email message is received, that signature is authenticated by the POP3/IMAP server using the public key. Thus, the recipient can easily recognize if the message is legitimate or if the sender’s address has been spoofed. A discrepancy will occur if the content of the email has been changed on its way as well, so DKIM can also be used to ensure that the sent and the received emails are identical and that nothing has been attached or removed. This email authentication system will increase your email safety, as you can verify the authenticity of the important email messages that you get and your colleagues can do likewise with the email messages that you send them. Based on the particular mail service provider’s adopted policies, a message that fails the check may be erased or may be delivered to the recipient’s mailbox with a warning flag.
