Here a list of files that are installed by Install Letter Opener.pkg:
- Macintosh HD/Library/Mail/Bundles/Letter Opener
- Macintosh HD/Library/Application Support/Letter Opener
- Macintosh HD/Application/Letter Opener Welcome
- $HOME/Library/Application Scripts/com.apple.mail/Letter Opener
Navigate to Library > Mail folder
- Open Finder
- Click Go > Go to Folder ...
- Enter /Library/Mail and click Go.
Detailed file list
You find a can detailed list of Install Letter Opener.pkg files by choosing File > Show Files from within the Installer.