DomainKeys is an e-mail authentication system designed to verify the DNS domain of an e-mail sender and the message integrity. The DomainKeys specification has adopted aspects of Identified Internet Mail to create an enhanced protocol called DomainKeys Identified Mail (DKIM). This merged specification became the basis for an IETF Working Group which guided the specification toward becoming an IETF standard.
Both DomainKeys and DKIM were published in May 2007. DomainKeys was issued as a "historical" protocol and DKIM was issued as its standards-track replacement.
