I'm experiencing a problem with Mail where the contents of certain mailboxes (folders) are not visible. In particular, I have a folder called Received in my Mail application where I store most of my old email. Navigating to ~/Library/Mail/Mailboxes/Received.mbox/Messages reveals that all the messages are indeed present. You can click on any .emlx file and an email comes up.
I've been messing around with trying to import the mailbox again and running the rebuild command with no luck.
Any tips on how to resolve this would be greatly appreciated.