Mbox files keep emails in a basic and very robust format that is easily imported in many other email programs and services. Exporting from Mac OS X Mail is a not always straightforward manner, but easy nonetheless.
Export a Mac OS X Mail Folder to an Mbox File
To save a folder as an mbox file from Mac OS X Mail:
- Open the folder in Mac OS X Mail.
- Make sure the folder contains all and only messages you want to export to the mbox file.
- Select Mailbox | Archive Mailbox… from the menu.
- Go to your Desktop under Choose a destination for mailbox archives….
- Click Choose.
- Open the Terminal application.
- Type "cd " (do not include the quotation marks but make sure there's a whitespace character following "cd").
- Drag and drop the "
.mbox" file from your Desktop to the Terminal window. - Hit Enter in the Terminal window.
- Type 'cp mbox "../
.mbx"'. - Do include the inner (double) but not the outer (single) quotation marks.
- Replace '
' with the exported Mac OS X Mail folder's name. If you have exported a folder named "Project Vayu", for instance, the line should read
cp mbox "../Project Vayu.mbx"
.- (You can use Tab to have Terminal complete the folder name.)
- Press Enter.
On your Desktop, you now have an .mbx file of your folder in mbox format. You can delete the .mbox file archived from Mac OS X Mail if you like.
Export Select Mac OS X Mail Messages to an Mbox File
You can also export just some emails to a mbox file from Mac OS X Mail:
- Highlight the messages you want to export in Mac OS X Mail.
- Select File | Save As… from the menu.
- Pick the desired folder and file name under Save As: and Where:.
- Make sure Raw Message Source is selected under Format:.
- Click Save.
- Optionally, click the saved file and add ".mbx" to its name to make the format known.

