Is there a reason why the message archives are public and the list is
unmoderated? It seems that might be the reason why the posting has
dramatically decreased. Generally members are likely to feel less
safe knowing that just anyone can read and join the group. When
spamming happens it is a strong reminder of this fact. If time is an
issue, although I'm a new member I'd be happy to try and moderate
membership for a little while to encourage more safe posting.

Just my .02

Erin