DomainKeys Identified Mail, or DKIM, is a system for validating the genuineness of an email message using a digital signature. When DKIM is activated for a particular domain, a public encryption key is published to the global Domain Name System and a private one is stored on the email server. If a new message is sent, a signature is issued using the private key and when the email is received, the signature is validated by the POP3/IMAP mail server using the public key. Thus, the receiver can easily know if the email message is legitimate or if the sender’s email address has been forged. A discrepancy will occur if the content of the email has been edited in the meantime as well, so DKIM can also be used to ensure that the sent and the delivered emails are identical and that nothing has been added or erased. This email validation system will heighten your email security, since you can validate the genuineness of the important email messages that you get and your partners can do likewise with the emails that you send them. Based on the particular mail service provider’s policies, an email that fails the examination may be removed or may appear in the recipient’s mailbox with a warning notification.