I've just updated the list settings in light of some recent spam.
Messages will be held for moderation. This is not great, but it will
help us to keep out obvious spam. When someone posts for the first
time, we'll either mark them as "whitelisted" so that all subsequent
messages do *not* get moderated and just go right through.
So, those of you who have been on the list for a while will see your
next message get held, but I'll keep on top of that to make sure
you're then whitelisted.
Sorry for the inconvenience.