Send a mail programmatically in Sprite Kit

I've tried to send mails programmatically using the MessageUI framework. This is what I have in MyScene.m. When I call the method, a mail window opens. But when I cancel the mail or when I send the mail, it doesn't goes back to MyScene.

    #import <MessageUI/MessageUI.h>
    -(void)sendMail
{
    MFMailComposeViewController *mc = [[MFMailComposeViewController alloc] init];
    mc.mailComposeDelegate = self;
    [mc setSubject:@"Subject"];
    [mc setMessageBody:@"Hello!" isHTML:NO];
    [mc setToRecipients:[NSArray arrayWithObject:@"my.email@gmail.com"]];

    // Present mail view controller on screen
    [self.view.window.rootViewController presentViewController:mc animated:YES completion:NULL];

}

- (void) mailComposeController:(MFMailComposeViewController *)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError *)error
{
    switch (result)
    {
        case MFMailComposeResultCancelled:
            NSLog(@"Mail cancelled");
            break;
        case MFMailComposeResultSaved:
            NSLog(@"Mail saved");
            break;
        case MFMailComposeResultSent:
            NSLog(@"Mail sent");
            break;
        case MFMailComposeResultFailed:
            NSLog(@"Mail sent failure: %@", [error localizedDescription]);
            break;
        default:
            break;
    }

    // Close the Mail Interface
    [self.view.window.rootViewController dismissViewControllerAnimated:YES completion:NULL];
}

You are setting the scene as a delegate for MFMailComposeViewController:

MFMailComposeViewController *mc = [[MFMailComposeViewController alloc] init];
mc.mailComposeDelegate = self;

Change it to

mc.mailComposeDelegate = self.view.window.rootViewController;

But that's of course a bad practice. SKScene is a presentation layer. You should present MFMailComposeViewController from UIViewController.

EDIT:

Add this code to GameSceneViewController:

- (void)viewDidLoad {
    [super viewDidLoad];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(sendMail) name:@"showMailComposer" object:nil];
}

-(void)sendMail
{
    MFMailComposeViewController *mc = [[MFMailComposeViewController alloc] init];
    mc.mailComposeDelegate = self;
    [mc setSubject:@"Subject"];
    [mc setMessageBody:@"Hello!" isHTML:NO];
    [mc setToRecipients:[NSArray arrayWithObject:@"my.email@gmail.com"]];

    // Present mail view controller on screen
    [self.view.window.rootViewController presentViewController:mc animated:YES completion:NULL];

}

- (void) mailComposeController:(MFMailComposeViewController *)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError *)error
{
    switch (result)
    {
        case MFMailComposeResultCancelled:
            NSLog(@"Mail cancelled");
            break;
        case MFMailComposeResultSaved:
            NSLog(@"Mail saved");
            break;
        case MFMailComposeResultSent:
            NSLog(@"Mail sent");
            break;
        case MFMailComposeResultFailed:
            NSLog(@"Mail sent failure: %@", [error localizedDescription]);
            break;
        default:
            break;
    }

    // Close the Mail Interface
    [self dismissViewControllerAnimated:YES completion:NULL];
}

Call this when you want to send a mail:

[[NSNotificationCenter defaultCenter] postNotificationName:@"showMailComposer" object:nil];