In Exim 4, there's no such thing as directors - you need to add a new router instead. Also, the canonical order of the configuration file was changed so routers come before transports, so the router for Exim 4 comes first here. Put this router somewhere after the ``begin routers'' line of your config file, and remember that order matters.
mailman_router: driver = accept require_files = MAILMAN_HOME/lists/$local_part/config.pck local_part_suffix_optional local_part_suffix = -bounces : -bounces+* : \ -confirm+* : -join : -leave : \ -owner : -request : -admin transport = mailman_transport