Undo Send on the Desktop
“Undo Send” was added to Gmail Labs years ago, and became an official, opt-in Gmail feature in 2015. With the launch of the new Gmail last year, Undo Send is now turned on by default and you can’t deactivate it. But you can adjust how long you have to unsend an email.
Log into Gmail, and click the Gear icon () on the upper-right and select Settings.
Under the General tab, scroll down to Undo Send. Click the drop-down menu and select whether you want the “Undo Send” option to appear for 5, 10, 20, or 30 seconds after you hit send.
Scroll to the bottom and click Save Changes. When you send an email, an Undo button will appear on the bottom left. Click Undo, and the email will return as a draft for you to continue editing.
Undo Send From the Gmail App
Once the feature is set up on desktop, Undo Send settings will apply to the Gmail mobile apps for iOS and Android. Now all you have to do is fire up the app, compose a new email, and send it on its merry way.
An Undo link will appear at the bottom of the screen and remain there for however many seconds you selected on the desktop. Tap Undo to be returned to your draft. The interface looks similar on iOS (left) and Android (right).
Confirm Before Sending on Android
Android users only recently received the ability to Undo Send from their phones. Previously, the best they could do was enable “Confirm before sending,” which—as its name suggests—produce a prompt that asks if you really want to send an email before it goes out.
For most of us, that’s probably overkill. But if you want to be extra cautious with your email, “Confirm before sending” is still available on Android (but not iOS).
To enable it in the Android Gmail app, click on the hamburger icon (), scroll to the bottom of the left pane, and tap Settings. At the Settings screen, tap General settings. Scroll to the bottom of the screen and tap on the checkmark next to “Confirm before sending” to enable the feature.
Now compose and try to send a new email. A message pops up asking if you want to send the message. Tap OK to send it or Cancel to stop it. If you cancel it, you then have a chance to review the message and make any changes before you attempt to resend it.