- This is how to configure a Yahoo group to eliminate spam:
Management -> Messages -> Posting and Archives (edit) -> Moderation: New
Each time a new member posts, the moderator will receive an email informing
them that they need to moderate. The moderator can click on the link
provided in the email, and if the message is not spam, they can approve it
and remove further moderation for this member.
This has completely eliminated spam from all of my Yahoo groups, and it
requires very little effort--most new members don't post, and most posts are
made by people who have posted before.