Rare is the email user who hasn't experienced the instantaneous regret associated with sending a message you really shouldn't have. For gmail users however, that feeling. could be about to become a thing of the past.

A new "undo send" feature has been made available from Gmail Labs, a collection of extra settings built into Google's free webmail which allow users to test-drive additions to the service developed by Google engineers.

Turning on 'undo send' builds in a five-second delay to the emailing process, during which the email is held in stasis, while an option to cancel sending is displayed to the user. If the "undo send" option is not selected the email will be delivered as usual.

Michael Leggett, a Gmail User Experience Designer, explained what prompted the development of the feature on Gmail's official blog: "Sometimes I regret sending a message the morning after. Other times I send a message and then immediately notice a mistake...I could undo just about any other action in Gmail — why couldn’t I undo send?"

Google have previously attempted to help users avoid sending emails they may later regret with "Mail Goggles", a service launched in October 2008 which made users answer a number of maths questions before their messages were sent, theoretically preventing intoxicated emailers from contacting anyone inappropriately.