How to get stationery back in Apple Mail on macOS Mojave?

You must have a copy of the following files from a computer running High Sierra (10.13) or lower In this example I used files from Sierra (10.12)

• /Applications/Mail/Contents/Resources/ComposeWindow.toolbar

• /Library/Application Support/Apple/Mail

If you would like the stationery in the original mail application then skip step 1, disable SIP, and continue with the original application, SIP can be reenabled after. Make copies of everything. Instead of "replace" add a .orig to the file extension.

1. Duplicate the Mail Application

2. Right click on the new Mail Application and go to /Contents/Resources/

3. Replace the ComposeWindow.toolbar with the ComposeWindow.toolbar from the copied files

4. Go to Finder>Go To Folder>/Library/Application Support/Apple/

5. Copy the Mail folder from the copied files to this folder

6. Open the Mail application and compose a new email

7. Right Click on the Toolbar and select Customize Toolbar

8. Drag the icon labeled Show Stationery to your toolbar and hit done

9. Click the Show Stationery button in your toolbar

Note: The toolbar item DOES work with dark mode but the Stationery Panel does not.

macOS Sierra (10.12) Files are available on Github → https://github.com/jbis9051/StationeryMailFiles