view release on metacpan or  search on metacpan

lib/App/Qmail/DMARC.pm  view on Meta::CPAN

package App::Qmail::DMARC;

our $VERSION = '0.61';

__END__

=head1 NAME

qmail-dmarc - verify using DMARC and queue a mail message for delivery

=head1 DESCRIPTION

qmail-dmarc is designed to be called by qmail-smtpd instead of qmail-queue
and will verify if incoming e-mail conforms to the DMARC policy of its
sender domain:

=over 4

=item 1.

If the environment variable C<RELAYCLIENT> exists, no verification is done,
and the e-mail is immediately passed to C<qmail-queue>.

=item 2.

In any other case, we check if the message contains a valid DKIM signature
matching the domain of the C<From:> header field.
If this is the case, the e-mail is passed to C<qmail-queue>.

=item 3.

If not, but the message has a C<From:> domain contained in
C</var/qmail/control/rcpthosts> and the environment variable C<DMARC_REJECT>
is set to a true value, the message is rejected with message
C<554 Valid DKIM signature required for sender domain ...>

=item 4.

If not, a SPF check is done, and a C<Received-SPF:> header field is added to
the message.
Then we check if the message is aligned with its sender's DMARC policy.
A C<DMARC-Status:> header field is added.

If the message does not align to the policy, the policy advises to reject such
messages and when the environment variable C<DMARC_REJECT> is set to a true
value, the message will be rejected with C<554 Failed DMARC test.>

=item 5.

In any other case the message is passed on to C<qmail-queue>.

=back

Diagnostic messages are written as a single line to standard error,
so you should find them in your C<qmail-smtpd>'s log.

=head1 OPTIONS

Apart from controlling the rejection of messages via the environment variable
C<DMARC_REJECT>, none.
It just works the way I need it.
If you need it to operate in any other way, please let me know.

=head1 BUGS

Please report any bugs or feature requests to
C<bug-app-qmail-dmarc at rt.cpan.org>, or through the web interface at
L<https://rt.cpan.org/NoAuth/ReportBug.html?Queue=App-Qmail-DMARC>.
I will be notified, and then you'll automatically be notified of progress on
your bug as I make changes.

=head1 SUPPORT

You can find documentation for this module with the perldoc command.