DomainKeys Identified Mail (DKIM) is an email authentication system used to confirm that an email message has been sent by an authenticated server or individual. An electronic signature is attached to the email’s header using a private key. When the message is received, a public key that is available in the global DNS database is used to confirm who exactly sent it and if the content has been changed in any way. The prime function of DKIM is to avert the widely spread scam and spam email messages, as it makes it impossible to forge an email address. If a message is sent from an email address claiming to belong to your bank or financial institution, for example, but the signature does not correspond, you will either not get the message at all, or you’ll get it with an alert that most probably it is not a legitimate one. It depends on email providers what exactly will happen with an email message that fails to pass the signature check. DKIM will also provide you with an extra layer of safety when you communicate with your business partners, for example, since they can see that all the e-mail messages that you exchange are authentic and haven’t been tampered with in the meantime.