How revoke a sent message in Gmail? 

There are cases when you accidentally send a text to the recipient while typing in Gmail. You can return a sent email within a certain time and it will not reach the user.

1. Go to the site https://mail.google.com/.
2. Open settings in the upper-right corner.
3. Go to the General tab.
4. in the "Cancel sending" section, click on the list containing seconds.
5. Set 30.

Now you can withdraw your messages within 30 seconds. After clicking the "Send" button, you will see the "Cancel" button next to the "Message sent"text.