After six years of beta testing, Gmail’s Undo Send feature is now available for all.
Using Undo Send, you can “unsend” e-mails up to ten seconds after you’ve hit the send button. For those that have the option enabled, Google will delay sending the mail until after the ten-second cancellation window. If you want to extend the window to recover your messages, you can do so by up to 30 seconds.
Source: iMore
