Mail::DKIM - Signs/verifies Internet mail with DKIM/DomainKey signatures


  # verify a message
  use Mail::DKIM::Verifier;

  # create a verifier object
  my $dkim = Mail::DKIM::Verifier->new();

  # read an email from stdin, pass it into the verifier
  while (<STDIN>)
      # remove local line terminators

      # use SMTP line terminators

  # what is the result of the verify?
  my $result = $dkim->result;


This module implements the various components of the DKIM and DomainKeys message-signing and verifying standards for Internet mail. It currently tries to implement these specifications:

RFC4871, for DKIM
RFC4870, for DomainKeys
draft-ietf-dmarc-arc-protocol-06, for ARC

The module uses an object-oriented interface. You use one of two different classes, depending on whether you are signing or verifying a message. To sign, use the Mail::DKIM::Signer class. To verify, use the Mail::DKIM::Verifier class. Simple, eh?

Likewise for ARC, use the ARC modules Mail::DKIM::ARC::Signer and Mail::DKIM::ARC::Verifier

If you're sending to test libraries which expect the tags in headers to be sorted, you can set $Mail::DKIM::SORTTAGS to a true value, and all created headers will get sorted keys


Mail::DKIM::Signer, Mail::DKIM::Verifier

Mail::DKIM::ARC::Signer, Mail::DKIM::ARC::Verifier


Problems passing `make test' seem to usually point at a faulty DNS configuration on your machine, or something weird about your OpenSSL libraries.

The "author signing policy" component is still under construction. The author signing policy is supposed to identify the practice of the message author, so you could for example reject a message from an author who claims they always sign their messages. See Mail::DKIM::Policy.

Please report bugs to the CPAN RT, or github issue tracker.


Jason Long, <>


Marc Bradshaw, <> Bron Gondwana, <> John Levine, <>


Copyright (C) 2006-2007, 2009 by Messiah College Copyright (C) 2017 by FastMail Pty Ltd Copyright (C) 2017 by Standcore LLC

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.6 or, at your option, any later version of Perl 5 you may have available.