protected function data()
    {
        $in = "DATA" . $this->CRLF;
        $code = $this->pushStack($in);
        if ($code !== '354') {
            throw new CodeException('354', $code, array_pop($this->resultStack));
        }
        $in = $this->message->toString();
        $code = $this->pushStack($in);
        if ($code !== '250'){
            throw new CodeException('250', $code, array_pop($this->resultStack));
        }
        return $this;
    }