public static function validate_email($mail) {
        if (strlen($mail) > 256) return false;
        $pattern = '#^\S{1,64}@\S+\.\S{2,6}$#i';
        return (bool) preg_match($pattern, $mail);
    }

      if (self::validate_email($email) !== true) {
        $this->action_out = "Fehler|Mail-Adresse scheint ungültig zu sein";
        $s = false;
      }