DomainKeys Identified Mail, or DKIM, is a system for checking the genuineness of an email message by using an e-signature. When DomainKeys Identified Mail is enabled for a certain domain, a public encryption key is published to the global Domain Name System and a private one is stored on the email server. If a new email is sent, a signature is issued using the private key and when the message is received, that signature is checked by the POP3/IMAP email server using the public key. In this way, the receiver can easily recognize if the email is authentic or if the sender’s address has been spoofed. A mismatch will appear if the content of the email has been edited in the meantime as well, so DomainKeys Identified Mail 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 validation system will enhance your email security, as you can confirm the authenticity of the important emails that you get and your colleagues can do likewise with the email messages that you send them. Based on the given email service provider’s adopted policies, an email that fails to pass the check may be erased or may end up in the recipient’s inbox with a warning sign.