Do not display new emails preview on mail mac

A common request!

To disable the preview of new emails in the Mail app on your Mac, you can follow these steps:

1. Open the Mail app on your Mac.
2. Click on "Mail" in the top menu bar and select "Preferences" (or use the keyboard shortcut Command + Comma).
3. In the Preferences window, click on the "General" tab.
4. Uncheck the box next to "Show preview" in the "New Mail" section.

Alternatively, you can also disable the preview of new emails by using the following Terminal command:

defaults write com.apple.mail DisableNewMailPreview -bool true

Once you've made this change, new emails will no longer be previewed in the Mail app.