Here is a cool feature from Google to undo send action of an email in Gmail. This feature was available for beta users from 2009. It proved very popular and hence Google decided to make it as an official feature. Here are steps to enable undo send on Gmail web client.
Log on to Gmail. Click on settings wheel and select ‘Settings’ option.
Under General settings, scroll and look for option ‘Undo Send’. Check on the check box to enable the setting and set required time period.
Hit ‘Save Changes’ button at the bottom of the settings page. This is important in order to reflect the changes. If you forget to save changes and try to navigate away from settings, you will see a pop-up asking for saving the changes.
Now let’s see what happens when an email is sent. When user clicks on ‘Send’, following notification is shown at the top.
Notice the addition of ‘Undo’ link in the notification. This link is shown only for the time period mentioned in the settings page. When user clicks on ‘Undo’ link, the mail opens in the Edit mode so that user can make required changes and resend the mail.
Note ( A small warning!): If you click on ‘View message’ link to check your mail for typos, you have lost your chance to ‘Undo’ it!