The feature delays your own outgoing message for a set number of seconds. After that, you can decide to delete it completely or make corrections. When 30 seconds have passed, the e-mail will be sent as usual this will be a welcome addition for mistakes or if you have forgot to add an attachment or perhaps wanted to say something and changed your mind.
How to set this up is simple.
Hit the Settings icon (GOG) on the top right hand side whilst your inbox is open,then hit Settings,scroll down to Enable Undo Send pictured above,tick the box on the left and you then have between 5 and 30 seconds to select which suits your needs,once you have chosen make sure you scroll down to the end of the page and select SAVE CHANGES.