Gmail undo Email That you sent

First, turn on Undo Send

On your computer, open Gmail.
In the top right, click Settings Settings and then Settings.
In the "Undo Send" section, check the box next to "Enable Undo Send."
In the "Send cancellation period" section, set the amount of time you want to decide if you want to unsend an email.
At the bottom of the page, click Save Changes.
Undo sending your message
After you turn on Undo Send, you can cancel sending an email.

After you send a message, you'll see the message "Your message has been sent" and the option to Undo or View message.
Click Undo.