SimpleEmailServiceMessage::setReturnPath PHP Method

    public function setReturnPath($returnpath)
    {
        $this->returnpath = $returnpath;
        return $this;
    }

 $mail->setSubject(stripslashes($confirmpageDet['email_subject']));
 $campaign_text_body = stripslashes($confirmpageDet['email_text']);
 $campaign_html_body = stripslashes($confirmpageDet['email_html']);
 if ($form_format == 'ft') {
     $body = $campaign_text_body;
 } else {
     $body = $campaign_html_body;
     $text_body = $campaign_text_body;
 }
 $confirmlink = $configDetails['siteUrl'] . "confirmform.php?form_submit_id=" . base64_encode($form_submit_id);
 $body1 = str_replace("%%CONFIRMLINK%%", $confirmlink, $body);
 $text_body1 = str_replace("%%CONFIRMLINK%%", $confirmlink, $text_body);
 $mail->setMessageFromString($text_body1, $body1);
 $mail->addTo($subscription_EmailId);
 $mail->addReplyTo("*****@*****.**");
 $mail->setReturnPath("*****@*****.**");
 $sendArray = "";
 $sendArray = $ses->sendEmail($mail);
 if ($sendArray['errorcode'] == '400') {
     $confirmpageDet1 = $dbClass->getTableRecordSingle("form_page", "form_id=? and page_type=?", array($formId, 'erropage'));
     if ($confirmpageDet1['url'] != '') {
         $url = $confirmpageDet1['url'];
         $url = "http://" . $url;
         pageRedirection($url);
         //header('Location:$url');
         //exit;
     } else {
         echo stripslashes($confirmpageDet1['confirm_html']);
     }
 }
 $mail->ClearTo();