DomainKeys Identified Mail, or DKIM, is a system for confirming the legitimacy of an email by using an e-signature. When DomainKeys Identified Mail 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 mail server. If a new message is sent, a signature is generated using the private key and when the email is delivered, that signature is verified by the POP3/IMAP mail server using the public key. In this way, the recipient can easily know if the email is legitimate or if the sender’s address has been spoofed. A discrepancy will occur if the content of the email message has been edited on its way as well, so DKIM can also be used to ensure that the sent and the received email messages are identical and that nothing has been added or deleted. This email validation system will increase your email security, as you can verify the authenticity of the important email messages that you receive and your partners can do likewise with the messages that you send them. Based on the given email provider’s adopted policy, an email message that fails to pass the test may be erased or may emerge in the recipient’s inbox with a warning.