Re: Anti-spam.

I am unsure what the current configuration is; however, I believe Mailman supports holding messages from non-members for moderator approval. https://www.gnu.org/software/mailman/mailman-admin/sender-filters.html -- Summer Tea Keyoxide: https://keyoxide.org/46C09BA8A20E5C501E1E05970B6D17F72BC47F61