Other Information
 - News
- Documentation
 - SourceForge Project Info
- DomainKeys Implementors mailing list
- DomainKeys Message Board


MTAs using DomainKeys
- Sendmail DomainKey Milter
- Qmail
- MS Exchange 2003
- qpsmtpd
 - Port 25's PowerMTA
- Etype.net's acSMTP
- ActivSoftware's XMServer
- OmniTI Ecelerity
- StrongMail
- DRCC no.Spam.java
- Exim 4.51
- Alt-N Technologies MDaemon MTA
- Postfix
- BorderWare MXtreme
- Communigate Pro
- IronPort
- Merak Mail
- L-Soft Listserv
- Mailtraq
- SocketLabs Hurricane MTA Server

SourceForge Logo

DomainKey Implementor's Tools and
Library for email servers & clients
Last Updated: August 28, 2007

This sourceforge project is no longer actively maintained. We expect many of the external links to degrade over time.
-- miles


The purpose of this project is to create a freely available library that can be easily adopted by most MTA and UA implementers to add DomainKeys (Historical RFC 4870) functionality. DKIM is the Standards Track RFC for email authentication. DKIM.org is actively maintained suporting the adoption of DomainKeys Identified Mail.

The DomainKeys Library was written in C and provided a foundation for implementing the DomainKeys email authentication system in mail transfer agents and mail user agents.


Royalty-free, worldwide, non-exclusive licensing information for this project is available here.


The source code for the latest libdomainkeys implementation can be downloaded here.

  The torturetest, commands, and CPAN packages contain canonicalization test files (and expected results), a CPAN structure, and verification and signing test command line tools.

Other Libraries
  Perl from killa.net.

C# from CERN.

DomainKey Setup Options
  How to generate a DomainKey public/private key-pair.
  Underscores are allowed in DNS records.
  A one page description of a few DomainKey distribution and DNS options is available.
  How to set up Sendmail to use DomainKeys and DomainKeys Identified Mail.
  How to set up Qmail to use DomainKeys.
  How to set up IronPort to use DomainKeys.
  How to set up Mdaemon to use DomainKeys.
  How to set up Exim to use DomainKeys.

DomainKeys DNS Testing Tools
  A DomainKey Policy Record Tester.
  A DomainKey Selector Record Tester.

Interoperability Testing
  There are several email addresses set up to autorespond to a DomainKey signed message with verification results. will forward mail to all of the addresses below.
  Sendmail's , Russell Nelson's Qmail , and Etype's can all verify nofws or simple canonicalization. Skylist has a webtool that will check DomainKeys, SPF, and Sender-ID.

  Mark Delany and Miles Libbey.

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