public function activateSender( $email, $code ) {
        if( empty( $email ) || empty( $code ) ) {
            return $this->handleError( 'Empty email or activation code' );
        }

        $data = array(
            'code' => $code
        );

        $requestResult = $this->sendRequest( 'senders/' . $email . '/code', 'POST', $data );

        return $this->handleResult( $requestResult );
    }