How to Undo Sent Mail on Gmail?

Composed a really personal mail on Gmail? And sent it to the wrong person? And wondered you could "undo" it??

This simple option on Gmail allows you to undo the sent mail. However, you cannot undo the already sent mails, but this will help you undo the sent mail after enabling the option.

Simple steps you need to follow:

1. Open Gmail and login to your account.
2. Click on the 'gear' icon on right side of the screen.
3. Then click on 'Settings'.
4. Settings page will open and under the 'General' tab you need to find 'Undo Send:'.
5. Check 'Enable Undo Send' option.
6. Select the number of seconds.
7. Scroll down and click on 'Save Changes'.
Done!

Next time after you send a mail, you'll see a new option 'Undo', on top of your screen.