What’s new in Mail on Mac?
The Mail app in macOS Monterey offers new features for sending, receiving, and viewing email messages.
When you first open Mail, you can choose to enable Protect Mail Activity to prevent senders from using messages to learn your IP address and about your activity in Mail. See Use Mail Privacy Protection.
Apps that you download from the App Store can include Mail extensions that help you send and receive messages. See Use Mail extensions.
The keyboard shortcut for showing and hiding the Mail sidebar is now Control-Command-S. See Use the sidebar in Mail.