#######################################################################
sub give_to_lost_letter_receiver {
    
    # Finally, if we haven't found -some- indication of who should
    # receive this, we'll send it to lost_letter_recipient.
    # $lost_letter_recipient can be unspecified, which would be
    # equivalent to saying "discard such mail entirely". Variable
    # $lost_letter_receiver could refer to a subdirectory of the
    # $mail_root if that's how things are arranged locally, or could
    # refer to any other 'live' address.
    
    $header{"Was-To:"} = $header{"To:"};
    $header{"To:"} = $lost_letter_receiver;
    $header{"Subject:"} = "(lost) " . $header{"Subject:"};

} #end of sub give_to_lost_letter_receiver