DomainKeys Identified Mail, or DKIM, is a system for confirming the legitimacy of an email message using an electronic signature. When DomainKeys Identified Mail is enabled for a particular domain name, a public encryption key is published to the global DNS 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 email is delivered, the signature is ‘scanned’ by the incoming server using the public key. In this way, the receiver can easily know if the email is legitimate or if the sender’s address has been forged. A discrepancy will occur if the content of the email has been modified on its way as well, so DKIM can also be used to make sure that the sent and the delivered email messages are identical and that nothing has been added or deleted. This email validation system will strengthen your email security, as you can validate the legitimacy of the important emails that you get and your associates can do the exact same thing with the email messages that you send them. Based on the given mail service provider’s policy, an email that fails to pass the test may be erased or may end up in the recipient’s inbox with a warning alert.
