I thought Yahoo Groups shut down some time ago?
I used to be on several thriving groups and was a moderator on one, they worked well and were very popular. Then Yahoo decided their platform looked dated and revamped everything, in the process completely ruining groups. The new design was so buggy it was unusable and members abandoned them almost overnight fleeing to other platforms. Despite outrage in the community Yahoo steadfastly refused to roll back the changes. Screw Yahoo, they did it to themselves.