NAME

       Courier::Filter::Module::FakeDate - Fake "Date:" message header filter module for the Courier::Filter
       framework

SYNOPSIS

           use Courier::Filter::Module::FakeDate;

           my $module = Courier::Filter::Module::Header->new(
               forward_tolerance   => {
                   # years, months, weeks, days, hours, minutes, seconds
                   hours       => 2
               },
               backward_tolerance  => {
                   # years, months, weeks, days, hours, minutes, seconds
                   days        => 5
               },

               ignore_unparseable  => 0,

               logger      => $logger,
               inverse     => 0,
               trusting    => 0,
               testing     => 0,
               debugging   => 0
           );

           my $filter = Courier::Filter->new(
               ...
               modules     => [ $module ],
               ...
           );

DESCRIPTION

       This class is a filter module class for use with Courier::Filter.  It matches a message if it has a
       "Date" header field that lies too far in the future or the past, relative to the local system's time.  If
       the message has a "Resent-Date" header field (see RFC 2822, 3.6.6), that one is examined instead, because
       the message could simply be an old one that has recently been re-sent, which is perfectly legitimate
       behavior.

       In the case of a match, the response tells the sender that their "Date" header is implausible and that
       they should check their clock.

       Note: Times in different time zones are compared correctly.

       Note: When using this filter module, it is essential that the local system's own clock is set correctly,
       or there will be an increased risk of legitimate messages getting rejected.

   Constructor
       The following constructor is provided:

       new(%options): returns Courier::Filter::Module::FakeDate
           Creates a new FakeDate filter module.

           %options is a list of key/value pairs representing any of the following options:

           forward_tolerance
           backward_tolerance
               The maximum durations by which a message's "Date" or "Resent-Date" header may diverge into the
               future and the past, respectively, from the local system's time.  Each duration must be specified
               as a hash-ref containing one or more time units and their respective quantity/ies, just as
               specified by DateTime::Duration.  "forward_tolerance" defaults to 2 hours.  "backward_tolerance"
               defaults to 5 days to account for transmission delays.

               For example:

                   forward_tolerance  => { hours => 4 },
                   backward_tolerance => { days  => 1, hours => 12 }

           ignore_unparseable
               A boolean value controlling whether messages whose "Date" or "Resent-Date" header does not
               loosely conform to RFCs 822 or 2822 should be ignored (true) or matched (false).  Defaults to
               false.

           All options of the Courier::Filter::Module constructor are also supported.  Please see "new" in
           Courier::Filter::Module for their descriptions.

   Instance methods
       See "Instance methods" in Courier::Filter::Module for a description of the provided instance methods.

SEE ALSO

       Courier::Filter::Module, Courier::Filter::Overview.

       For AVAILABILITY, SUPPORT, and LICENSE information, see Courier::Filter::Overview.

AUTHOR

       Julian Mehnle <julian@mehnle.net>