public function is_valid() {
        $ret = false;

        if (is_null($this->masterName) === false && is_null($this->fromName) === false &&
            is_null($this->fromDomain) === false && is_null($this->division) === false &&
            is_null($this->encoding) === false && is_null($this->subject) === false &&
            is_null($this->deliveryType) === false && is_null($this->friendlyFrom) === false &&
            is_null($this->description) === false && is_null($this->campaign) === false
        ) {
            $ret = true;
        }

        return $ret;
    }