Have you ever hit send on an email and immediately realized that you made a mistake, forgot to copy someone on it or didn’t include some important details? Did you know that for a brief period of time you can unsend an email in Gmail? Here’s how:

• Compose an email in Gmail and hit Send.
  A black box will appear in the bottom left-hand corner of your screen displaying:
  • Message sent
  • Undo
  • View message
• Click Undo to reopen the email and update your message.
• Hit Send to resend the message. 

Change the undo send cancellation period

The default setting to undo a sent email is 5 seconds. To change the undo send cancellation period: 

• In Gmail, click the Settings icon in the upper right-hand corner. 
• Click See all settings.
• Under the General tab, locate Undo Send. 
• Change the Send cancellation period from 5 seconds to 10, 20 or 30 seconds. 
• Scroll to the bottom of the page and click Save Changes.