DomainKeys Identified Mail, or DKIM, is a system for verifying the legitimacy of an email by using an e-signature. When DomainKeys Identified Mail is activated for a specific domain name, a public key is published to the global DNS system and a private one is stored on the mail server. If a new email is sent, a signature is generated using the private key and when the message is received, the signature is ‘scanned’ by the POP3/IMAP server using the public key. Thus, the receiver can easily recognize if the email message is legitimate or if the sender’s email address has been forged. A mismatch will appear if the content of the email has been edited on its way 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 increase your email safety, as you can validate the genuineness of the important emails that you get and your partners can do the exact same thing with the emails that you send them. Based on the particular mail service provider’s policies, a message that fails the check may be removed or may enter the receiver’s inbox with a warning alert.