I have a VPS with (name hidden to protect company). My web sites and email services all run from this single VPS (terrible I know, but money prohibits expansion). One of my customers web sites got hacked and corrupted permissions on the entire server. It had to be rebuilt, and restored from a backup. All the mail that was on the server between the backup and current day were lost. Somehow, thunderbird, didn't keep copies like it usually does. It deleted all the folders and files associated with the missing data. I have been using thunderbird for over 15 years, and this is the first time I have had this happen. Any known way to recover those missing folders and all that mail? It is causing customers to lose business, and makes me look like a complete moron. Thanks for any and all help.

For reference purposes, server uses IMAP, folders were synchronized, keep messages, check, never delete messages, check, show only subscribed folders- unchecked.