#!/usr/bin/env perl
use strict;
use warnings;
use WWW::Mailman;
use Getopt::Long;
use YAML::Tiny qw( LoadFile DumpFile Dump );

my %param = (
    config => 'mailman.yml',
    cookie => 'mailman.cookie',
);
GetOptions( \%param, 'config=s', 'cookie=s' )
    or die "Usage: $0 [ --config file ] [ --cookie file ]\n";

my $lists = LoadFile( $param{config} );
my %opt = ( cookie_file => $param{cookie} );

# actual code

# I want to receive duplicates!
for my $list ( values %$lists ) {
    my $mm = WWW::Mailman->new( %opt, %$list );
    $mm->options( { nodupes => 0 } );
}