The desktop version of Gmail is able to undo sending an email. The feature delayed the actual sending of the email for a short time so you can hit undo if you made a mistake or wrote something stupid. But the feature has not been available on Android until now.
The latest version of Gmail (version 8.7) now allows you to undo a sent email by default, though we’re not sure if this is necessarily an app version feature or a server side rollout feature yet.
When you send an email, a black bar at the bottom lets you know that the email has been sent. There’s now an undo button lingering for a while in case you need it.
If you’ve updated to the latest version of Gmail for Android, give it a shot! It’s great to see this feature finally hit our phones. It might save us one day.