gistfile1.txt

            $output = fopen("php://output",'w') or die("Can't open php://output");
            header("Content-Type:application/csv");
            header("Content-Disposition:attachment;filename=pressurecsv.csv");
            fputcsv($output, ['email','status','created on', 'end date', 'last logged in', 'sales email']);
            foreach($contentArray as $content) {
                fputcsv($output, $content);
            }
            fclose($output) or die("Can't close php://output");
            exit;

gistfile2.txt

            $response = $this->getResponse();
            $headers = $response->getHeaders();
            $headers->addHeaderLine('Content-Type', 'text/csv');
            $headers->addHeaderLine('Content-Disposition', "attachment; filename=\"pressurecsv.csv\"");
            $headers->addHeaderLine('Accept-Ranges', 'bytes');
            $headers->addHeaderLine('Content-Length', strlen($content));

            $response->setContent($content);
            return $response;