public function sendOutput()
    {
        if ($this->binary) {
            $rcmail = rcmail::get_instance();
            $rcmail->output->future_expire_header(10 * 60);

            header('Content-Type: ' . $this->mimetype);
            header('Content-Size: ' . strlen($this->binary));
            echo $this->binary;

            return true;
        }

        return false;
    }