public function getTo()
 {
     if ($this->InboundToID) {
         return $this->InboundTo()->Email;
     }
     $arrEmails = array();
     $arrIDs = explode(',', $this->ToID);
     foreach ($arrIDs as $iID) {
         if ($member = PostmarkHelper::find_client($iID)) {
             $arrEmails[] = $member->Email;
         }
     }
     return implode(', ', $arrEmails);
 }