<env:Envelope xmlns:env='http://schemas.xmlsoap.org/soap/envelope/'>
   <env:Header xmlns:wsa='http://www.w3.org/2005/08/addressing'>
      <wsa:To>http://business456.example/client1</wsa:To>
      <wsa:Action>http://fabrikam123.example/ReplyPO</wsa:Action>
      <wsa:RelatesTo>uuid:6B29FC40-CA47-1067-B31D-00DD010662DA</wsa:RelatesTo>
      <ns1:sessionid wsa:IsReferenceParameter='true' xmlns:ns1='http://somens'>someuniqueid</ns1:sessionid>
   </env:Header>
   <env:Body/>
</env:Envelope>