Fast Mbox Editor is a handy tool for mbox bundles exported by Apple Mail or any other program using the “Export Mailbox” features. While Apple Mail takes a significant amount of time exporting the mbox files, this app can open them for viewing in a fraction of a second. It is extremely useful when you have an archive of Apple Mail exported mboxes, because you will be able to open a file also of many gigabytes without any issue, and, as said, in a fraction of a second. Now compatible with mbox files not created by Apple Mail.