How to undo sent emails? Firstly, I didn't know such a feature exists in Gmail. This is an useful feature the helps you stop sent mails in case you sent them by mistake or with some errors. This feature gives you a maximum of 30seconds to stop the sent mails. 30seconds is not enough? First check if you have enabled UNDO SENT MAILS options in your Gmail. undosend2.jpg Sign in to your Gmail account and go to Settings(Top right hand corner) Click on Labs on the settings page, scroll down to reach UNDO SEND. Enable/Disable the option. Settings for Gmail. undosend3.jpg Scroll down to find Undo send . Enable and select your time option. [5,10,20,30] You are done. How to undo send? undosend.jpg This works perfectly and recommended too! Great! Thanks. Saw this on youtube video a while ago and never used it. Originally Posted by fogest Thanks. Saw this on youtube video a while ago and never used it. This feature is nothing new, its been there for a while now! nice find