Here's one I think you and everyone will like.

Top row, just to right of spell check, is a new icon - a life preserver.

Behind the scenes when you are entering a message it is now saved every 40 seconds. When it is saving, the life preserver will animate. In addition to saving every 40 seconds, it saves on exit. Doesn't save anything until at least 50 characters are in the message, this includes characters in the html code.

Result, if you lose your message text for any reason, click on the life preserver and it will restore the last saved item. Saves are kept for about 20 minutes.