MFMailComposeViewController和隐私 - 隐藏To:字段？

import MessageUI

class ViewController: UIViewController, MFMailComposeViewControllerDelegate {

    func sendEmail() {
        if MFMailComposeViewController.canSendMail() {
            let mailComposer = MFMailComposeViewController()
            mailComposer.mailComposeDelegate = self
            mailComposer.setToRecipients([])
            mailComposer.setSubject("邮件主题")
            mailComposer.setMessageBody("邮件正文", isHTML: false)
            present(mailComposer, animated: true, completion: nil)
        } else {
            print("无法发送邮件")
        }
    }

    func mailComposeController(_ controller: MFMailComposeViewController, didFinishWith result: MFMailComposeResult, error: Error?) {
        controller.dismiss(animated: true, completion: nil)
    }
}