How to Reset the Mac Mail App to Factory Fresh

Time needed: 10 minutes

To completely reset the Mail app on a Mac using macOS (as if you would uninstall and reinstall the application):

1. Export all emails stored only in Mail for macOS.

   Where: These are the emails under On my Mac.
   Here’s how: How to Copy “On My Mac” Email Folders.

2. Close Mail.

3. Open Finder.

4. Go to the ~/Library folder.

   Here’s how: Press Command Shift G for the Go to Folder shortcut and type ~/Library, for example, the click Go.

5. Highlight the Mail folder.

   Background: Mail is the folder where Mail stores emails on a Mac.

6. Press Enter to start renaming the folder.

   Other ways to rename: You can also right-click the folder, of course, and select Rename from the menu.

7. Type Mail.old or another name (other than Mail).

   

8. Press Enter again.

9. Now go to the ~/Library/Preferences/ folder.

10. Highlight the com.apple.mail.plist file.

    How: You can start typing com.apple.mai to jump to the file.
    Search: You can also press Command F and search for mail.plist, of course.
    Not found: If you cannot find the file, no matter; skip the next three steps.

11. Press Enter to start renaming the file.

12. Type com.apple.mail.plist.old.

13. Press Enter again.

14. Go to the ~/Library/Containers folder.

15. Highlight all folders called Mail.

    How: You can draw an outline with the mouse or hold down Command while clicking folders.
    Just one: If you see just one folder called Mail, do highlight it.

16. Select File | New Folder with Selection or File | New Folder with "Mail" from the menu.

    Finder keyboard shortcut: You can also press Command Control N.

17. Type Mail.old as the new folder’s name.

    

18. Press Enter.

19. Open System Settings (or System Preferences).

20. Open the Internet Accounts category.

21. Turn off Mail for all accounts you want to remove.

    Enabled email accounts. Mail will re-create and download again all accounts for which Mail is enabled.
    New accounts: You can also remove and re-add email accounts to re-create them with new settings.

22. Start Mail.

    IMAP will return: Mail uses IMAP email accounts, which store messages and folders on the server; after you reset Mail and added accounts back, the emails will return.

23. Eventually, if everything works fine: Delete the Mail.old folders and the com.apple.mail.plist.old file.

    Their word: You can find some information on resetting Mail on an Apple support forum.