Glad that you got a new mail provider. The old one owes you a refund! It started working again late this afternoon.
Yesterday, after seeing 2 weeks of posts and content go Poof! I got really concerned when I updated an open tab on a followed post and the site took me to a completely unrelated post in a different forum. Knowing something about databases this would indicate that the database index had been corrupted. It looks like you were able to recover most of the site from backups.