One of the most useful features present in Gmail for ages is the ability to undo a sent email. Sometimes this saves you from saying something you shouldn’t have or allows you to add something you forgot. Either way, it can be a real lifesaver when you need it and the Gmail app on Android now has it.
The ability to undo a sent email seems so simple and yet essential, it’s hard to believe it wasn’t implemented earlier. No one knows what took Google so long to add this to the Gmail app for Android or when it got added. We only know that it was sometime recently. This option has been a staple feature in Gmail on the web for years now. I can remember when it was first introduced as a Labs feature and I enabled it immediately.
Previously in the Gmail app for Android after sending an email you would see a toast message at the bottom that said sending message. However, with this feature, a little bar shows up at the bottom with sent and an undo button on the right side. This looks very similar to the notification bar you get when you delete an email with the same undo option.
According to Android Police, it is unknown whether it is a server-side change or part of the app itself. All we know is it appears to be an option in versions 8.7+ of the Gmail app. Android Police also claims that you can recall Gmail to Gmail emails before the sender has seen it. In my own testing, I was not able to achieve this, however.
In any case, it’s better to not linger too long and hit undo quickly if you think you made a mistake. You can always send the email again but once it is out there then you can never take it back.