locked about messages from non-members
This feature would make groups consultable. Of course messages from non-member should always be moderated. Ideally, the entire thread that results should be sent to the person who started it (unless a moderator prevents that).
I don't like the idea of routing messages from non-members to the owner-adress.
In my experience it causes confusion (moderators don't always notice it's meant for the entire group) and thus delays.