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Courier::Filter::Module::Header(3pm) User Contributed Perl Documentation Courier::Filter::Module::Header(3pm)


Courier::Filter::Module::Header - Message header filter module for the Courier::Filter framework


    use Courier::Filter::Module::Header;
    my $module = Courier::Filter::Module::Header->new(
        fields      => \%patterns_by_field_name,
        response    => $response_text,
        logger      => $logger,
        inverse     => 0,
        trusting    => 0,
        testing     => 0,
        debugging   => 0
    my $filter = Courier::Filter->new(
        modules     => [ $module ],


This class is a filter module class for use with Courier::Filter. It matches a message if one of the message's header fields matches the configured criteria.


The following constructor is provided:

Creates a new Header filter module.

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

Required. A reference to a hash containing the message header field names and patterns (as key/value pairs) that messages are to be matched against. Field names are matched case-insensitively. Patterns may either be simple strings (for exact, case-sensitive matches) or regular expression objects created by the "qr//" operator (for inexact, partial matches).

So for instance, to match any message from the "debian-devel" mailing list with the subject containing something about 'duelling banjoes', you could set the "fields" option as follows:

    fields      => {
       'list-id'    => '<>',
        subject     => qr/duell?ing\s+banjoe?s?/i
A string that is to be returned literally as the match result in case of a match. Defaults to "Prohibited header value detected: <field>: <value>".

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.


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

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


Julian Mehnle <>

2022-10-21 perl v5.34.0