While pressing “send” on Twitter, Facebook, and Snapchat, spells doom for something you immediately regret sending, Gmail has a feature buried within its vast ecosystem that lets you delete an email you may have sent in a fit of anger to your boss or girlfriend.
In order to enable the feature, log into Gmail and head to the settings option on the right of your screen indicated by the 
button.
Once you’ve done that:
- Select Settings.
- Select the Labs button (not Labels), which is located at the end, right before Themes.
- Scroll down to about the bottom of the list and find the “Undo Send” option.
- Hit “Enable,” then save.
- Once you’ve done that, hit the again and hit Settings.
- From there, scroll down under General and find the Undo Send option. From there, you’ll be able to control how long you have to unsend your email after you hit send. (Either 5, 10, 20, or 30 seconds.)
If you send an email, and option will appear on top of the screen with the undo button.
Voila. The option essentially holds your email for the allotted amount of time you chose in the settings. So when you press send, the email will remain in limbo until the time is up. Either way, those precious few seconds could mean the difference between you keeping a job, or getting something nice for Christmas from your boo.
[Complex]