DomainKeys Identified Mail, or DKIM, is a system for verifying the genuineness of an email message using a digital signature. When DomainKeys Identified Mail is activated for a specific domain, a public key is published to the global DNS 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, that signature is authenticated by the incoming server using the public key. Thus, the receiver can easily recognize if the email message is authentic or if the sender’s email address has been forged. A discrepancy will appear if the content of the email has been changed in the meantime as well, so DomainKeys Identified Mail can also be used to ensure that the sent and the received messages are identical and that nothing has been attached or removed. This email validation system will strengthen your email safety, since you can validate the genuineness of the important email messages that you receive and your colleagues can do the same with the email messages that you send them. Depending on the particular email service provider’s policies, a message that fails to pass the test may be deleted or may reach the recipient’s mailbox with a warning sign.