NAME
Mail::DMARC::PurePerl - a perl implementation of DMARC
VERSION
version 0.20130507
METHODS
init
Resets the Mail::DMARC object, preparing it for a fresh request.
validate
discover_policy
is_aligned
is_dkim_aligned
is_spf_aligned
is_subdomain
has_valid_reporting_uri
get_organizational_domain
exists_in_dns
Determine if a domain exists, reliably. The DMARC draft says:
9.6 If the RFC5322.From domain does not exist in the DNS, Mail Receivers
SHOULD direct the receiving SMTP server to reject the message {R9}.And in Appendix A.4:
A common practice among MTA operators, and indeed one documented in
[ADSP], is a test to determine domain existence prior to any more
expensive processing. This is typically done by querying the DNS for
MX, A or AAAA resource records for the name being evaluated, and
assuming the domain is non-existent if it could be determined that no
such records were published for that domain name.
The original pre-standardization version of this protocol included a
mandatory check of this nature. It was ultimately removed, as the
method's error rate was too high without substantial manual tuning
and heuristic work. There are indeed use cases this work needs to
address where such a method would return a negative result about a
domain for which reporting is desired, such as a registered domain
name that never sends legitimate mail and thus has none of these
records present in the DNS.I went back to the ADSP (which led me to the ietf-dkim email list where some 'experts' failed to agree on The Right Way to test domain validity. They pointed out: MX records aren't mandatory, and A or AAAA aren't reliable.
Some experimentation proved both arguments in real world usage. This module tests for existence by searching for a MX, NS, A, or AAAA record. Since this search may be repeated for the Organizational Name, if the NS query fails, there is no delegation from the TLD. That has proven very reliable.
fetch_dmarc_record
get_from_dom
get_dom_from_header
external_report
verify_external_reporting
AUTHORS
Matt Simerson <msimerson@cpan.org>
Davide Migliavacca <shari@cpan.org>
COPYRIGHT AND LICENSE
This software is copyright (c) 2013 by The Network People, Inc..
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.