mbx
===

A high performance mbox-replacement created by Marc Crispin of University of
Washington for UW-IMAP. Each message in the file is preceded by a record
carrying all the metadata that IMAP-protocol needs. This allows changing the
metadata easily by modifying the fixed-size header, rather than moving data
around in a file like with mbox.

File locking is handled more intelligently (only appends may need to wait for
locks), making this format a good choice for shared mailboxes.

Downsides contain:

 * Messages don't get deleted from disk until there's only one client accessing
   the mailbox, so you may need to add some forced downtime to get it done.
 * Works only in local filesystem.
 * Expunging is still as costly and as fragile as with mbox. 

(This file was created from the wiki on 2009-03-02 04:42)
