BCC multiple adresses

$this->autoRender = false;

		$content = $this->request->data['editor'];

		$title = 'Newsletter R.T.S';
		$name = 'R.T.S. Ieper';
        $from_address = 'noreply@rts.be';
		// $to = '';
		// $subscribers = $this->Newsletter->find('all');
		// foreach ($subscribers as $key => $subscriber) {
		// 	$to .= $subscriber['Newsletter']['email'] . ',';
		// 	// echo $subscriber['Newsletter']['email'] . '<br/>';
		// }

		// $to = rtrim($to, ',');
		$to = 'degry.thomas@gmail.com, thomas.degry@student.howest.be, evegar1@live.com.mx';
		$email = file_get_contents('http://' . $_SERVER['HTTP_HOST'] . $this->base . '/newsletter.html');

		$email = str_replace('{{year}}', date('Y'), $email);
		$email = str_replace('{{content}}', $content, $email);
		$email = str_replace('{{title}}', $title, $email);

		$headers = "MIME-Version: 1.0\r\n";
        $headers .= "Content-Type: text/html; charset=utf-8\r\n";
        $headers .= "Content-Transfer-Encoding: 8bit\r\n";
        $headers .= "X-Mailer: PHP/". phpversion();

        $headers .= "From: =?UTF-8?B?". base64_encode($name) ."?=  <$from_address>\r\n";
		$headers .= 'BCC: '. $to . "\r\n";

		mail(null, $title, $email, $headers);
		echo 'done';
		die();