public function deleteIdentity($identity)
    {
        $this->_action = 'DeleteIdentity';
        $this->_method = 'GET';
        $this->_refreshDate();

        if (!(filter_var($identity, FILTER_VALIDATE_EMAIL) || preg_match('/^([a-z\d]+(-[a-z\d]+)*\.)+[a-z]{2,}$/', $identity))) {
            throw new Exception('Identity must be EmailAddress or Domain');
            return;
        }

        $parameters = array(
            'Identity' => $identity
        );

        $this->_generateSignature($parameters);
        $res = $this->_request();
        if ($res['code'] == 200) {
            return (string) $res['body']->ResponseMetadata->RequestId;
        } else {
            return new SimpleEmailServiceError((string) $res['body']->Error->Code);
        }
    }