DomainKeys Identified Mail (DKIM) lets an organization take responsibility for a message that is in transit.  The organization is a handler of the message, either as its originator or as an intermediary. Their reputation is the basis for evaluating whether to trust the message for further handling, such as delivery. Technically DKIM provides a method for validating a domain name identity that is associated with a message through cryptographic authentication.

Popular links:

The DKIM.org website is hosted by Mutual Internet Practices Association (MIPA).

DKIM attaches a new domain name identifier to a message and uses cryptographic techniques to validate authorization for its presence. The identifier is independent of any other identifier in the message, such in the author's From: field.

The first version of DKIM synthesized and enhanced Yahoo!'s DomanKeys and Cisco's Identified Internet Mail specifications. It was the result of a year-long collaboration among numerous industry players, during 2005, to develop an open-standard e-mail authentication specification. Participants included Alt-N Technologies, AOL, Brandenburg InternetWorking, Cisco, EarthLink, IBM, Microsoft, PGP Corporation, Sendmail, StrongMail Systems, Tumbleweed, VeriSign and Yahoo!. The team produced the initial specification and several implementations. It then submitted the work to the IETF for further enhancement and formal standardization.

The result is a set of IETF specifications and supporting documentation.

A number of organizations have offered Press Contacts for matters relating to DKIM.

The current specifications are recommended for immediate use:

• DKIM Service Overview, RFC 5585
    »  html, pdf, txt 
• DKIM Signatures
    »  RFC 6376
• DomainKeys Identified Mail (DKIM) Development, Deployment and Operations, RFC 5863 
    »  html, txt
• DKIM Author Domain Signing Practices (ADSP)
   »  RFC 5617

See this list of Organizations Providing Software, Hardware or Services with DKIM.

Lars Eggert maintains a tally of the DKIM adoption rate.

Consulting

See this list of Consulting Services for assisting with DKIM development or deployment and use

An operations-related mailing list is available: dkim-ops.

Development

For general discussion with other DKIM developers, join the dkim-dev mailing list.

For quick questions to developers primarily active with OpenDKIM, there is an #dkim IRC channel at efnet.org.

Related Work

• IETF REPUTE Working Group

• Reporting of DKIM Verification Failures, draft-kucherawy-dkim-reporting » txt

• Abuse Feedback Reporting Format (ARF) » home

• Message Header Field for Indicating Message Authentication Status (Auth-Results) » txt » mailing list

• Vouch By Reference (VBR) » home

Yahoo's DomainKeys resulted in an Intellectual Property Rights claim concerning that applies to the DKIM specification.