Send a typed email message. The command-line below continues after pressing Enter key. Input CC email-id (optional) press Enter key. Input message text (can be multiline). Press Ctrl-D key to complete the message text

The command operates on the user's mailbox if no argument is given.
To send an email the message body is built from standard input.
More information: <https://manned.org/mail>.
Trick copyright: tl;dr; <https://github.com/tldr-pages/tldr>

mail --subject="{{subject line}}" {{[email protected]}}

click the source code to copy install mail on any operating system with command-not-found.com