Google The updated DomainKeys Identified Mail (DKIM2) permits an organization that owns the signing domain to claim some responsibility for a message by associating the domain with the message through a digital signature. This is done by publishing to Domain Name Service (DNS) of the domain a public key that is then associated to the domain and where messages can be signed by the corresponding private key. Assertion of responsibility is validated through a cryptographic signature and by querying the Signer’s domain directly to retrieve the appropriate public key. This document describes DKIM2 DNS record format and how to find the record.