Skip to main content


About DKIM

DKIM (DomainKeys Identified Mail) is a method to validate the authenticity of email messages using public-key cryptography. Simply, it is a way to verify that an email sender is who they say they are. Its purpose is to prevent email spoofing.

DKIM is a development of 'DomainKeys' from Yahoo and 'Identified Internet Mail' from Cisco, hence the name DKIM.

How DKIM works

  1. The sending domain publishes two TXT records to their DNS record: one is their public key, the other is the DKIM policy.

  2. The outbound email contains a DKIM signature generated by the sending mail server.

  3. The public key is used by the recipient mail server to verify the DKIM signature.


DKIM TXT records should be added to the domains DNS before enabling DKIM signing for a domain.

Go to System Settings > Mail Relay > DKIM to configure DKIM. See Configuring DKIM in SpamTitan Gateway.