Mail Goggles, available at Google Labs, tries to prevent drunk e-mailing.

Google Mail has invented a way of stopping you sending emails that may later prove embarrassing.

Intended to help you overcome the urge to say what you really think late on a Friday night when you are a little the worse for wear, Google’s Mail Goggles asks you to solve “a few simple math problems after you click send to verify you’re in the right state of mind”.

Of course, you have to enable the feature first – Google isn’t trying to force you to take an unwelcome arithmetic test every time you want to send a message – and even if you do enable it, it doesn’t assume you’re drunk all the time.

“By default, Mail Goggles is only active late night on the weekend as that is the time you’re most likely to need it. Once enabled, you can adjust when it’s active in the General settings,” said Jon Perlow, a Gmail engineer.

Note: You can activate the feature in your Gmail or Google Mail account by clicking on the Settings tab on the top right of the screen and selecting Labs. Scroll down and you should find a brief explanation of the Mail Goggles feature and the option to enable it.