Can't dismiss MFMailComposeViewController in Swift 3.0

The MFMailComposeViewController cannot be dismissed after pressing cancel or send button. I have added MFMailComposeViewControllerDelegate in my class but still, it's not working?

Here is my code:

func sendEmail() {
    let MailVC = MFMailComposeViewController()
    MailVC.mailComposeDelegate = self
    MailVC.setToRecipients(["\(emailLabel?.text)"])
    MailVC.setSubject("Set your subject here!")
    MailVC.setMessageBody("Hello this is my message body!", isHTML: false)
    // Present the view controller modally.
    self.present(MailVC, animated: true, completion: nil)
}

func mailComposeController(controller: MFMailComposeViewController,
                           didFinishWithResult result: MFMailComposeResult, error: NSError?) {
    // Dismiss the mail compose view controller.
    controller.dismiss(animated: true, completion: nil)
}