Basics of in-app email?

What classes am I looking in to? I'd like to allow the user to to "order" something via email in the app. i would like to use a modal view to show an email form which is pre-poulated.

Can someone please explain the process of sending an in-app email like this or refer me to the proper documentat开发者_StackOverflow中文版ion?

Apple's iPhone SDK documentation has some information about using in-app email:

• Using the Mail Composition Interface, iPhone Application Programming Guide
• MFMailComposeViewController class reference (this is the view controller a user sees when writing an email)

The link "Using the Mail Composition Interface" from the answer above redirects to "About iOS Programming" and I don't think it is a good start point for someone who needs an in-app mail composing tutorial.

There is a sample project on Apple's site that can give you a very good understanding of the process if you need such and it also provides ready to go code that you can integrate in your project with a bit of coding. The sample project - here.