DomainKeys Identified Mail, or DKIM, is a system for validating the authenticity of an email using an e-signature. When DomainKeys Identified Mail is enabled for a given domain, a public encryption key is published to the global DNS database and a private one is kept on the mail server. When a new message is sent, a signature is issued using the private key and when the email is delivered, that signature is checked by the receiving server using the public key. In this way, the receiver can easily know if the message is legitimate or if the sender’s address has been spoofed. A mismatch will occur if the content of the email message has been edited on its way as well, so DomainKeys Identified Mail can also be used to ensure that the sent and the delivered messages are identical and that nothing has been attached or removed. This authentication system will increase your email safety, since you can confirm the legitimacy of the important emails that you receive and your partners can do the same with the email messages that you send them. Depending on the given mail service provider’s adopted policy, a message that fails to pass the check may be removed or may show up in the receiver’s inbox with a warning flag.
