Similar to https://forum.howtoforge.com/threads/moved-invalid-maildir-to-corrupted-maildirs-folder.81439/ (Moved invalid maildir to corrupted Maildirs folder). It’s happened to me now too, and 17 GB of emails have vanished from one mailbox. Feature request: Is it possible to send a notification to the administrator when mailboxes are moved to /var/vmail/corrupted/? That way, I would have spotted it before the customer did ;-).