Recall Accidental E-mails with Gmail Undo Send
So you finally wrote that e-mail telling the boss where to stick it. You'd never send it, of course, but it sure felt good to write it. So you click Cancel and -- wait, oh no, you clicked Send by mistake! (Wasn't it Freud who said there are no accidents?) Fortunately, there's a way around these and other forehead-smacking boo-boos: Gmail's new Undo Send feature.
To enable it, click the Settings link, then Labs, and then scroll down until you find Undo Send. Set it to Enable and then click Save Changes.
Now, after you compose and send an e-mail, you have a "grace period" of about four seconds to click the Undo link that appears near the top of the screen.
Doing so returns you to the e-mail so you can make any necessary changes or delete your unwise diatribe forever.
If this sounds a little familiar, you may be thinking of Google's other Labs experiment for forgetful users: the Forgotten Attachment Detector. Thank you, Gmail, for saving us from ourselves! [via PC World]