Note: The Dmail extension has been discontinued.
Sending an email by mistake is a small disaster that can affect even the most cautious Gmail users. Although there is an option in Gmail to undo a sent email, the feature only work up to 30 seconds after you hit send. Sometimes that is too short a time to notice your error. I found a Chrome extension that solves this issue and more!
The Dmail Chrome Extension (website) not only allows you to set a time at which the email will be destroyed in the future before sending it, but you can also revoke the email at any time in the future. You no longer relinquish control of your emails after they are sent. Try it out for yourself and enjoy the ability to change your mind about the emails you send.