DomainKeys Identified Mail (DKIM) is an email validation system used to check that an e-mail message has been sent by an authenticated server or person. An e-signature is added to the header of the message using a private encryption key. When the email message is received, a public key that’s available in the global DNS database is used to verify who actually sent it and if its content has been edited in some way. The fundamental job of DKIM is to block the widely spread scam and spam messages, as it makes it impossible to fake an email address. If an email message is sent from an address claiming to belong to your bank, for example, but the signature doesn’t match, you will either not receive the message at all, or you’ll receive it with a warning notice that most likely it is not authentic. It depends on email providers what exactly will happen with an email that fails the signature examination. DomainKeys Identified Mail will also supply you with an added safety layer when you communicate with your business partners, for instance, since they can see for themselves that all the emails that you send are authentic and haven’t been modified in the meantime.