    # File bin/experimental-filter.rb, line 164
    def main

      # Read the .rdeliver file, which fills in the Deliver class.
      $config = '.rdeliver'

      # FIXME: make errors logged from this a lot more clear.
      eval(IO.readlines($config, nil)[0].untaint,
           Deliver.module_eval('binding()'),
           $config)

      begin
        toucher_thread = Thread.start {
          loop {
            now = Time.now
            File.utime(now, now, File.join("Maildir", ".filter.lock"))
            sleep(60)
          }
        }
        loop {
          process_queue
          sleep(15)
        }
      ensure
        Thread::kill(toucher_thread) if toucher_thread
        File::delete($lock_file_name)
      end
    end