I've had this problem, too. Yahoo will NEVER delete the group. And as long as spammers are posting, it'll live on forever.
My advice: In the old group, set up a monthly recurring calendar event & make sure to set a reminder. This event should say something like "If you're looking for DPhiE conversation, please join [new yahoogroup]. This yahoogroup is currently unmoderated and is the target of spammers." And then I usually add "This message will be automatically sent every month."
Good luck w/ your new group! And if you can, please post a note inviting everyone to the SororityAlumnae (formerly "Panhellenic") yahoogroup (link in my sig).
