Programming your iPhone application to set up an email for the user to send is easy, as long as you don’t mind it quitting your application. The following code will open the Mail application with a new email ready to be sent with the given email address, subject, and email body.

NSString *emailLink = [NSString stringWithFormat:@" Subject&body=%@", [@"This is the body of the email message" stringByAddingPercentEscapesUsingEncoding:NSASCIIStringEncoding]];
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:emailLink]];

This works the same way as clicking a ‘mailto:’ link on a web page.