DomainKeys Identified Mail, or DKIM, is a system for confirming the legitimacy of an email by using an e-signature. When DomainKeys Identified Mail is enabled for a certain domain, a public encryption key is published to the global Domain Name System and a private one is stored on the email server. When a new email is sent, a signature is generated using the private key and when the email message is received, the signature is verified by the incoming POP3/IMAP mail server using the public key. Thus, the recipient can easily tell if the email message is authentic or if the sender’s address has been spoofed. A mismatch will appear if the content of the email message has been altered on its way as well, so DKIM can also be used to ensure that the sent and the delivered email messages are identical and that nothing has been added or removed. This email authentication system will increase your email security, since you can confirm the authenticity of the important emails that you receive and your associates can do the exact same thing with the emails that you send them. Depending on the given mail service provider’s adopted policy, an email that fails to pass the check may be removed or may reach the receiver’s inbox with a warning notification.