Sending email message from the app using MFMailComposeViewController in MessageUI on iPhone

// Header file

// importing the MessageUI framework
#import <MessageUI/MessageUI.h>

// adding the delegate functionality to the class (<MFMailComposeViewControllerDelegate>)
@interface TutorialProjectViewController : UIViewController <MFMailComposeViewControllerDelegate> {

}

- (IBAction)pressTheMailButtonDudeFunction:(id)sender;



// Implementation file

- (IBAction)pressTheMailButtonDudeFunction:(id)sender {
	
	// allocatind new message composer window
	MFMailComposeViewController *mc = [[MFMailComposeViewController alloc] init];
	
	// setting a delegate method to "self"
	mc.mailComposeDelegate = self;
	
	// pre-populating the message subject
	[mc setSubject:@"Send me a message"];
	
	// adding content of the message as a plain text
	[mc setMessageBody:@"Send me a message is you like this tutorial :)" isHTML:NO];
	
	// adding content of the message as an HTML
	[mc setMessageBody:@"<p>Send me a message is you like this tutorial :)<p>" isHTML:YES];
	
	// adding recipients
	[mc setToRecipients:[NSArray arrayWithObjects:@"Fuerte <info@fuerte.cz>", @"info@xprogress.com", nil]];
	
	// adding recipients for a send copy to (arrayWithObject or arrayWithObjects)
	[mc setCcRecipients:[NSArray arrayWithObject:@"test@example.com"]];
	
	// adding hidden recipients
	[mc setBccRecipients:[NSArray arrayWithObject:@"test@example.com"]];
	
	// adding image attachment
	// getting path for the image we have in the tutorial project
	NSString *path = [[NSBundle mainBundle] pathForResource:@"Extra_Xcode_100x100" ofType:@"png"];
	
	// loading content of the image into NSData
	NSData *imageData = [NSData dataWithContentsOfFile:path];
	
	// adding the attachment to he message
	[mc addAttachmentData:imageData mimeType:@"image/png" fileName:@"My tutorial image"];
	
	// setting different than the default transition for the modal view controller
	[mc setModalTransitionStyle:UIModalTransitionStyleCrossDissolve];
	
	/*
	 Modal view controllers transitions:
	 
	 UIModalTransitionStyleCoverVertical => pops up from the bottom, default transition
	 UIModalTransitionStyleCrossDissolve => fade on the screen
	 UIModalTransitionStyleFlipHorizontal => page flip
	 */
	
	// displaying our modal view controller on the screen (of course animated has to be set on YES if you want to see any transition)
	[self presentModalViewController:mc animated:YES];
	
	// releasing the controller
	[mc release];
}

// delegate function callback
- (void)mailComposeController:(MFMailComposeViewController *)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError *)error {
	// switchng the result
	switch (result) {
		case MFMailComposeResultCancelled:
			NSLog(@"Mail send canceled.");
			/*
			 Execute your code for canceled event here ...
			 */
			break;
		case MFMailComposeResultSaved:
			NSLog(@"Mail saved.");
			/*
			 Execute your code for email saved event here ...
			 */
			break;
		case MFMailComposeResultSent:
			NSLog(@"Mail sent.");
			/*
			 Execute your code for email sent event here ...
			 */
			break;
		case MFMailComposeResultFailed:
			NSLog(@"Mail send error: %@.", [error localizedDescription]);
			/*
			 Execute your code for email send failed event here ...
			 */
			break;
		default:
			break;
	}
	// hide the modal view controller
	[self dismissModalViewControllerAnimated:YES];
}

Don't forget to import the MessageUI framework into your project :)