// Displays an email composition interface inside the application. Populates all the Mail fields. 
- (void) displayComposerSheet:(NSString *)body {
	
	MFMailComposeViewController *tempMailCompose = [[MFMailComposeViewController alloc] init];
	
	tempMailCompose.mailComposeDelegate = self;
	
	//[tempMailCompose setToRecipients:[NSArray arrayWithObject:@"[email protected]"]];
	//[tempMailCompose setCcRecipients:[NSArray arrayWithObject:@"[email protected]"]];
	[tempMailCompose setSubject:@"iPhone App recommendation"];
	[tempMailCompose setMessageBody:body isHTML:NO];
	
	[self presentModalViewController:tempMailCompose animated:YES];
    [tempMailCompose release];
}

// Dismisses the email composition interface when users tap Cancel or Send. Proceeds to update the message field with the result of the operation.
- (void)mailComposeController:(MFMailComposeViewController*)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError*)error {	
	// Notifies users about errors associated with the interface
	switch (result)
	{
		case MFMailComposeResultCancelled:
			NSLog(@"Result: canceled");
			break;
		case MFMailComposeResultSaved:
			NSLog(@"Result: saved");
			break;
		case MFMailComposeResultSent:
			NSLog(@"Result: sent");
			break;
		case MFMailComposeResultFailed:
			NSLog(@"Result: failed");
			break;
		default:
			NSLog(@"Result: not sent");
			break;
	}
	[self dismissModalViewControllerAnimated:YES];
}

// Launches the Mail application on the device. Workaround
-(void)launchMailAppOnDevice:(NSString *)body{
	NSString *recipients = [NSString stringWithFormat:@"mailto:%@?subject=%@", @"[email protected]", @"iPhone App recommendation"];
	NSString *mailBody = [NSString stringWithFormat:@"&body=%@", body];
	
	NSString *email = [NSString stringWithFormat:@"%@%@", recipients, mailBody];
	email = [email stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
	
	[[UIApplication sharedApplication] openURL:[NSURL URLWithString:email]];
}

// Call this method and pass parameters
-(void) showComposer:(id)sender{
	Class mailClass = (NSClassFromString(@"MFMailComposeViewController"));
	if (mailClass != nil){
		// We must always check whether the current device is configured for sending emails
		if ([mailClass canSendMail]){
			[self displayComposerSheet:sender];
		}else{
			[self launchMailAppOnDevice:sender];
		}
	}else{
		[self launchMailAppOnDevice:sender];
	}
}

http://yasirmturk.com

Add MessageUI.framework reference

then in header file

#import <MessageUI/MessageUI.h>
#import <MessageUI/MFMailComposeViewController.h>
#import <MessageUI/MFMessageComposeViewController.h>

Display Email Composer on iPhone SDK

iphone

Objective C