Undo Your Send
Have you heard the news? Gmail has made "undoing" your email a real thing. If you make a typo or regret sending a message, you can undo the action by enabling "Undo send." This new setting gives you the option to take back a message you just sent. The catch? You have to enable the Undo Send option and then you have to do it within seconds of hitting send.
Here's how to enable it:
-Click the gear in the top right .
-Scroll down to "Undo Send" and click Enable.
-Set the cancellation period (the amount of time you have to decide if you want to unsend an email).
-Click Save Changes at the bottom of the page.
Click here for more details.