Не отсылает сообщение на почту при отправители, почему?

public function sendMail($from, $to, $text, $subject = null, $copy = null)
    {
        $result = array();
        
        if (!preg_match("/^([a-z0-9_\.-]+)@([a-z0-9_\.-]+)\.([a-z\.]{2,6})$/",$from)) {
            return 'Wrong format mail from';
        } elseif (!preg_match("/^([a-z0-9_\.-]+)@([a-z0-9_\.-]+)\.([a-z\.]{2,6})$/",$to)) {
            return 'Wrong format mail to';
        }
        
        $subject = '=?UTF-8?B?'.base64_encode($subject).'?=';
		$headers = "From: $from\r\n";
        
        if ($copy) {
            if (!preg_match("/^([a-z0-9_\.-]+)@([a-z0-9_\.-]+)\.([a-z\.]{2,6})$/",$copy)) {
                return 'Wrong format mail reply';
            } else {
                $headers .= "Bcc: $copy\r\n";
            }
        }
        
        $headers .= "MIME-Version: 1.0\r\n";
        $headers .= "Content-Type: text/html; charset=utf-8\r\n";
        $headers .= "Content-Transfer-Encoding: base64\r\n"; 
        $text = base64_encode($text);
        
        return mail($to, $subject, $text, $headers);