exporting email from Mail to folder outside of Mail

Exporting a mailbox from the Mail app sidebar copies it to the selected destination, leaving the mailbox and its mails intact in the Mail app. After checking that the export worked (you should see an .mbox file…this is your exported mailbox!) you can then safely delete the mailbox from the Mail app sidebar if you wish. The .mbox exported mail box can at any time be re-imported from within the Mail app using the mailbox import function and selecting the .mbox.

If you want to export multiple mailboxes you can just select them in the Mail app sidebar as you would multiple files or folders in a Finder window, and then export them. Exporting a mailbox in my experience only takes a few seconds at most, even for a large number of mails.

You can open the “table of contents” in TextEdit to have a look, but it´s of no use except to the Mail app. and should be left alone! Don´t change anything as that would make any later re-importing to Mail impossible!

Hope all this is clear and helps you! Regards, Ian.

You're very welcome RumiKern, glad to have been of help! I learned the hard way about all this mailbox business, by stupidly losing a lot of very old mails which had sentimental value. Live and learn! Cheers, Ian.