I write for a living, and yet recently, I almost sent an email to a colleague that mentioned the “League of Women Biters” instead of the “League of Women Voters.” You can probably relate ― who among us hasn’t had that stomach-churning, nail-biting moment when you realize autocorrect has twisted your correspondence into something risqué or worse?

It’s happened to me far too many times to count. But I’ve largely managed to escape embarrassment thanks to a Gmail setting that has been saving me from cringeworthy moments like this for more than a decade: “undo send.”

The feature dates back to March 2009, according to Harry Maugans, a cybersecurity expert with Privacy Bee, but almost nobody knew about it for years. “Google parked it in a testing area called Gmail Labs, which you had to dig into in the settings and turn on yourself,” he explained. “The feature actually didn’t become a built-in part of Gmail until 2015. So for about six years, it was sitting right there and most people had no idea.”

Many still don’t, even though Gmail is overwhelmingly the most popular email service in the United States, according to market reports. Three-quarters of Americans have Gmail accounts, compared with just 31% who use Yahoo mail, the next most popular service. I stumbled across this Gmail hack by accident, when someone mentioned it in a long-ago comment thread.