The Domain Keys Identified Mail (DKIM) Internet standard enables email senders to digitally sign their messages so that receivers can verify that those messages have not been forged. The DKIM sender authentication scheme allows the recipient of a message to confirm a message originated with the sender’s domain and that the message content has not been altered. A cryptography-based solution, DKIM provides businesses an industry-standard method for mitigating email fraud and protecting an organization’s brand and reputation at a relatively low implementation cost. Learn more about DKIM.

DKIM has been approved by the IETF as a draft standard (RFC 4871). The protocol was developed through the cooperation of Sendmail, Cisco Systems and Yahoo!

Since being approved by the IETF, a new open source project was started. The OpenDKIM Project is a community effort to develop and maintain a C library for producing DKIM-aware applications and an open source milter for providing DKIM service.

The project started from a code fork of version 2.8.3 of the open source dkim-milter package developed and maintained by Sendmail, Inc.

The Sendmail Sentrion Message Processing Engine comes standard with OpenDKIM.

More information is available at opendkim.org and dkim.org