We're working on a process for migrating mailboxes from Windows and non-control-panel servers to our cPanel servers. One dovecot feature that would help a lot is the "master user", with full access to all mailboxes. I tried getting that feature working on our development cPanel server, but without luck. It would authenticate, but then give an error like "Permission denied creating default INBOX". Has anybody got this working, and care to share the magic sauce?