DomainKeys Identified Mail, or DKIM, is a system for validating the authenticity of an email message using an e-signature. When DomainKeys Identified Mail is activated for a given domain name, a public key is published to the global Domain Name System and a private one is kept on the email server. If a new email is sent, a signature is generated using the private key and when the email message is received, the signature is checked by the incoming POP3/IMAP email server using the public key. Thus, the recipient can easily discern if the email message is legitimate or if the sender’s address has been spoofed. A discrepancy will occur if the content of the email has been modified in the meantime as well, so DKIM can also be used to make sure that the sent and the received emails are identical and that nothing has been attached or erased. This email authentication system will increase your email security, as you can validate the authenticity of the important emails that you receive and your associates can do likewise with the emails that you send them. Depending on the given email provider’s policy, an email message that fails to pass the examination may be erased or may enter the recipient’s inbox with a warning sign.
