DomainKeys Identified Mail, or DKIM, is a method for confirming the authenticity of an email message by using an electronic signature. When DKIM is enabled for a given domain name, a public cryptographic key is published to the global DNS system and a private one is kept on the email server. When a new email message is sent, a signature is generated using the private key and when the email is delivered, the signature is ‘scanned’ by the receiving server using the public key. Thus, the recipient can easily know if the email is genuine or if the sender’s address has been forged. A discrepancy will occur if the content of the email message has been changed on its way as well, so DKIM can also be used to make sure that the sent and the delivered email messages are identical and that nothing has been added or erased. This email authentication system will increase your email security, as you can confirm the authenticity of the important emails that you receive and your partners can do the exact same thing with the email messages that you send them. Depending on the particular email provider’s policy, an email that fails to pass the test may be removed or may enter the receiver’s mailbox with a warning sign.