I've been trying to configure mailman to reject non-member posts to wikiis-l, I've succeeded in making it reject any non-member posts and send the poster a message saying that hir mail has been moderated, however what I've not been able to configure is the message sent in this email, currently it is:
""" You are not allowed to post to this mailing list, and your message has been automatically rejected. If you think that your messages are being rejected in error, contact the mailing list owner at wikiis-l-owner@wikimedia.org. """
I set member_moderation_notice in http://mail.wikipedia.org/mailman/admin/wikiis-l/privacy/sender to something entirely different, without success.