Occasionally, usually after a system crash, I get corrupted mbx format mailboxes.
I assume that you already are taking remedial action on whatever is causing those system crashes, including such things as using an uninterruptable power supply.
Is there a tool for repairing, or simple documentation on how to do so?
Some people have written their own tools. Here's information in the FAQ on what you need to know:
http://www.washington.edu/imap/IMAP-FAQs/index.html#7.15
I can see the messages in the file, but get "Error opening or locking INBOX" messages in the log files.
That message is a catch-all from the POP3 server, and as you can expect isn't particularly useful. Pine, the IMAP server, or (as you noticed) mailutil will provide better information.
Unable to parse internal header at 13815331: 4Rgxf3J0BM5PembZO3ouNqzT778
This specific error is the most common encountered with a corrupt mbx format mailbox, and is covered in the IMAP FAQ including what to do.
Please let me know if you need any more help.
-- Mark --
http://staff.washington.edu/mrc Science does not emerge from voting, party politics, or public debate. Si vis pacem, para bellum.