public function exportList($listId, $exportType, $exportFormat, $exportColumns = array(), $email = null, $fileEncoding = null, $addToStoredFiles = false, $dateStart = null, $dateEnd = null, $useCreatedDate = false, $includeLeadSource = false, $listDateFormat = null)
    {
        $data["Envelope"] = array(
            "Body" => array(
                "ExportList" => array(
                    "LIST_ID" => $listId,
                    "EXPORT_TYPE" => $exportType,
                    "EXPORT_FORMAT" => $exportFormat
                )
            )
        );

        if ($exportColumns) {
            foreach ($exportColumns as $column) {
                $data["Envelope"]["Body"]["ExportList"]["EXPORT_COLUMNS"]["COLUMN"][] = $column;
            }
        }

        if ($email) {
            $data["Envelope"]["Body"]["ExportList"]["EMAIL"] = $email;
        }

        if ($fileEncoding) {
            $data["Envelope"]["Body"]["ExportList"]["FILE_ENCODING"] = $fileEncoding;
        }

        if ($addToStoredFiles) {
            $data["Envelope"]["Body"]["ExportList"]["ADD_TO_STORED_FILES"] = "";
        }

        if ($dateStart) {
            $data["Envelope"]["Body"]["ExportList"]["DATE_START"] = $dateStart;
        }

        if ($dateEnd) {
            $data["Envelope"]["Body"]["ExportList"]["DATE_END"] = $dateEnd;
        }

        if ($useCreatedDate) {
            $data["Envelope"]["Body"]["ExportList"]["USE_CREATED_DATE"] = "";
        }

        if ($includeLeadSource) {
            $data["Envelope"]["Body"]["ExportList"]["INCLUDE_LEAD_SOURCE"] = "";
        }

        if ($listDateFormat) {
            $data["Envelope"]["Body"]["ExportList"]["LIST_DATE_FORMAT"] = $listDateFormat;
        }

        $response = $this->_request($data);
        $result = $response["Envelope"]["Body"]["RESULT"];

        if ($this->_isSuccess($result)) {
            if (isset($result['JOB_ID']))
                return array("JOB_ID" => $result['JOB_ID'], "FILE_PATH" => $result['FILE_PATH']);
            else {
                throw new \Exception('Export list created but no job ID was returned from the server.');
            }
        } else {
            throw new \Exception("exportList Error: ".$this->_getErrorFromResponse($response));
        }
    }