ZDNet: “With this Gmail feature, you have up to 30 seconds to catch and unsend a grammar mistake, a misspelled name, or even the wrong recipient before it’s cast into someone’s inbox abyss. Gmail has an Undo Send feature that gives you up to a 30-second grace period after you send an email, so you can sneakily proofread before the message disappears from your grasp. Here’s how to enable the feature.”