Fix Blank Preferences in Mac Mail (Apple Mail)

Short answer:
If Mac Mail Preferences appears blank, reset the Mail app by removing local Mail data and containers. This forces macOS to rebuild the settings.

Summary: If you open Mail > Preferences and see a blank window with no options, the Mail app configuration may be corrupted. Follow the steps below to reset the app and restore the Preferences view.

If you see a blank Preferences window like below, follow the steps to resolve it:

Steps to fix blank Preferences in Mac Mail

1. Quit the Mail app completely
   Make sure Mail is fully closed. Open Activity Monitor and confirm that Mail is not running.
2. Open Finder and go to:
   Go > Go to Folder
3. Rename the following folder:

~/Library/Mail

4. Delete the following folder:

~/Library/Containers/com.apple.mail

5. Reopen the Mail app.

What happens next

Apple Mail will automatically re-download your mailbox data (IMAP folders) and recreate the Preferences configuration.

Cleanup

After confirming that Mail is working correctly, you can delete the renamed ~/Library/Mail folder.

Next steps

Return to Mail > Preferences and verify that the Signatures section is now accessible.