We migrated our Yahoo! Group to a self-hosted Discourse! Almost 40,000 posts were imported, and user accounts were created for the group's existing subscribers.
The forum and your preferences can be accessed at https://forum.lpsf.org or via mobile apps.
Discourse is heavily customizable, so if it's not working the way you want, login and change your settings, or let me know.
More info on the migration is at: https://forum.lpsf.org/t/migration-from-yahoo-groups-to-a-self-hosted-di...