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 given domain, a public encryption key is published to the global Domain Name System and a private one is kept on the mail server. When a new email message is sent, a signature is issued using the private key and when the message is received, the signature is verified by the incoming server using the public key. In this way, the receiver can easily distinguish if the message is genuine or if the sender’s address has been forged. A discrepancy will occur if the content of the email has been changed 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 authentication system will heighten your email security, as you can confirm the genuineness of the important emails that you get and your partners can do likewise with the messages that you send them. Based on the given email provider’s policies, a message that fails to pass the test may be deleted or may be delivered to the recipient’s mailbox with a warning.
