public function postContacts($email)
    {
        $url = $this->getApiEndpoint() . self::REST_CONTACTS;
        $data = [
            'Email' => $email,
            'EmailType' => 'Html',
        ];
        $this->setUrl($url)
            ->setVerb('POST')
            ->buildPostBody($data);

        $response = $this->execute();

        if (isset($response->message)) {
            $message = $email . ' , url ' . $url . ', ' . $response->message;
            $this->helper->debug('postContacts', [$message]);
        }

        return $response;
    }