pro tip: if you clear the "ubbt_PRIVATE_MESSAGE_USERS" database for the single user id who is asking for them to be removed, then when you run the CONTENT REBUILDER ( Prune Orphaned Private Messages ), all their PM will be cleared. And I believe the pruning is also triggered each time any user logs in... along with subscriptions and the post view counter.
I also believe that I posted in another thread, the SQL that would turn off all auto emails for users who have not logged in within 24months. You could just stick that in to a weekly cron task.
