I thought I had enabled moderation of posts from non-members - but it didn't take.
I got the the setting panel and select that option, but what I "save" it reverts to "no moderation"
Weird.
I tried setting to "moderate all message" and that worked. So I'm leaving it there. There is so little real traffic I doubt anyone will notice. I'll aim to approve genuine messages within a day or so.
If it ever seems not to be working I might take you up on the offer to help moderate - but that would require figuring out exactly how to do it .... so its for another day :-)
NeilBrown