There is nothing worse in this world than sending out an important email to a potential employer for example and later discovering that ugly typo you made that could ruin it all for you. Mistakes in online communication are so common that two Harvard Law graduates decided to make a company that makes them disappear.
Lindsay Lin and David Gobaud created the free online service called Pluto Mail. Its most influential and amazing feature is the ability to edit already sent emails. It even gives you the opportunity to un-send messages. Even more amazingly you can use your own email client while the receiving end does not necessarily have to be subscribed to Pluto Mail. You can even set your e-mails to auto-expire in anytime you want.
Lin and Gobaud designed the service from their dorm rooms while receiving guidance and coaching tips from the experts from the Harvard Innovation Lab. You can subscribe for Pluto Mail here: https://www.sendpluto.com/