Excluding certain Postbox files from Time Machine on Mac OS X
posted this on February 09, 2010 01:43 PM
Note: With Postbox 2.1.2 and higher - if the user account has admin privileges when running Postbox, Postbox will automatically exclude IMAP mail folders while preserving IMAP mail filters via time Machine. So the instructions below no longer apply to admin accounts on Mac OS X.
Postbox's mail format is one-file-per-folder (also known as the "mbox" format) which can result in very large Time Machine backups.
To solve this problem, you can exclude the ImapMail folder from being backed up on Time Machine as this information is already backed up on the server.