Sending E-mail from within Your App with the Message UI Framework

While it has always been possible to send e-mail from within an iPhone application using a mailto: URL, doing so has been a jarring experience for the user, as using a mailto: URL kicks the user out of the currently running application and launches the Mail application. This, needless to say, does not result in an ideal user experience. Furthermore, the amount of customizability in terms of not just composing the e-mail itself, but also in terms of being able to take action after the e-mail has been sent, has been very limiting.