- 
What is digest called on STDOUT?
    %config_out_london = (
        title                   => 'London.pm',
 - 
Where do digests, new threads and archived threads go?
        dir_digest              => "$topdir/london",
        dir_threads             => "$topdir/london/Threads",
        dir_archive_top         => "$topdir/london/Threads/archive",
 - 
Where do auxiliary files go?
        archived_today          => "$topdir/london/archived_today.txt",
        de_archived_today       => "$topdir/london/de_archived_today.txt",
        deleted_today           => "$topdir/london/deleted_today.txt",
        digests_log             => "$topdir/london/digests_log.txt",
        digests_read            => "$topdir/london/digests_read.txt",
        todays_topics           => "$topdir/london/todays_topics.txt",
        mimelog                 => "$topdir/london/mimelog.txt",
 - 
How are messages numbered and delimited inside thread files?
        id_format               => 'sprintf("%03d",$1) . 
                                        \'_\' . sprintf("%04d",$2)',
        output_id_format        => 'sprintf("%04d",$1)',
        thread_msg_delimiter    => "--__--__--\n\n",
 - 
Flags for archiving, deletion, MIME cleanup; options
        MIME_cleanup_log_flag   => 1,
        archive_kill_trigger    => -1,
        archive_kill_days       => 14,
        digests_read_flag       => 0,
        archive_config          => 0,
        optional_fields         => [ qw( org to cc date reply_to ) ],
    );