macOS: Archiving Messages from Apple Mail (Redux!)

Back in 2014, I wrote a tip about how to archive your messages out of Apple Mail using the “Export Mailbox” option.

macOS Mail Mailbox Menu showing Export Mailbox

That still works (as long as you’re aware of the caveat at the end of this article), so if you’re looking to clean up your Mail program, go check it out. However, there’s one piece of it that needs an update. As it turns out, Apple has now hidden the “Export all subfolders” checkbox under a button, and if you aren’t paying attention, you could end up deleting critical info! Here’s how it works now: As I mentioned in the previous tip, you’ll click on your mailbox from the sidebar, and then you can right-click on it to choose “Export Mailbox” from the contextual menu or pick that option from the menus at the top (shown in my screenshot above). Whichever way you do it, though, Mail will next want to know where you intend to store your mbox file.

macOS Mail Export Mail dialog Options Button

See that “Options” button I’ve called out? Underneath that is the very important checkbox that you’ve gotta toggle on if the mailbox you’re exporting has subfolders.

macOS Mail Export Mail dialog showing "Export all subfolders" Checkbox

If you forget to do this and then delete the originals from Mail…well, you’ll be sad. For example, here is a section of some of my saved mailboxes:

macODS Mail Mailboxes with Subfolders ready to export

If I exported those without “Export all subfolders” on, then I’d be saving “Work TO DO,” “TO KEEP,” and “Electronic Receipts,” but not the folders underneath them. Bad, bad, bad, wrong. I’m not sure why Apple made this choice—it’s not as if this saves a bunch of screen space or anything!—but as long as you’re aware of what you’re doing, everything should be OK.

Also, you used to be able to use Mail’s Window > Activity menu item to monitor your export’s progress. This often no longer works; now you’ll need to find the mbox files you exported, and if the process isn’t complete, you’ll see “partial” in the file name.

macOS Mail Mailbox Export showing email export in progress with "partial" in the file name

Finally, here’s the caveat: I’ve found these exports to be more persnickety and prone to failure in recent versions of macOS than before, so if you decide to attempt this, be sure you’ve got good backups in place and watch the progress carefully. What I’ve been doing as well is reimporting the mbox files after the export (using the steps in my previous tip) before I delete the originals. Once I make sure everything in the reimported mailbox matches the original, I then delete both the original and the newly imported one. This assures me that if I ever need to use those saved-out mbox files in the future, they’ll be accurate. Paranoid? Yes. But thorough? You betcha.

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Thank-you for your reply Melissa! I don’t like the “cloud” nor any web based Mail (Gmail, Yahoo all have been hacked) hence why 100 megs is no big deal to me because in the past it made no difference if I trashed everything off webmail from time to time because I had everything safe on the mothership. POP v IMAP, ey? Also, we lost the “delete messages from the server” checkbox in Apple’s infinite wisdom. You think I could re-set back to POP ? I’m grandfathered into a good speed v cost with e-link dsl that nobody else can match… Read more »


Thanks for the excellent article. If you are serious about archiving email, MailSteward is worth checking out:


I’ve got a “MAIL” question for Melissa – and I don’t know where to post it so here goes… I just put Sierra (not High Sierra) on a 2006 Mac Pro that had Yosemite on it. I use earthlink dsl for ISP for a LONG time. Now, as opposed to EVER before back to pre Tiger days – when I delete email from e-link’s Webmail server (which says it now supports IMAP mail) it ALSO deletes the MAIL from my Mac!! Very frustrating!!! I only get 100 megs free storage on elink’s server so I need to empty it about… Read more »