DomainKeys Identified Mail, or DKIM, is a system for verifying the authenticity of an email by using a digital signature. When DKIM is activated for a particular domain name, a public encryption key is published to the global DNS database and a private one is stored on the mail server. When a new email message is sent, a signature is generated using the private key and when the email message is received, that signature is ‘scanned’ by the incoming POP3/IMAP email server using the public key. Thus, the receiver can easily distinguish if the message is genuine or if the sender’s email address has been forged. A discrepancy will appear if the content of the email has been altered on its way as well, so DomainKeys Identified Mail can also be used to make sure that the sent and the received emails are identical and that nothing has been added or deleted. This authentication system will heighten your email safety, since you can confirm the genuineness of the important emails that you get and your associates can do the exact same thing with the emails that you send them. Based on the particular mail service provider’s policies, an email message that fails to pass the test may be removed or may appear in the recipient’s inbox with a warning sign.
