BizTalk 2013 WCF-BasicHttpRelay & proxy server

Can anyone answer what the supported way for exposing a WCF-BasicHttpRelay receive location through a proxy is?

We have tested the proxy with WcfBasicHttp and WcfWebHttp send ports successfully utilising the BizTalk host credentials that run the receive location.

To get the receive location to work we have tried putting the default proxy against the BTSNTSvc.exe.config files using both these approaches and neither appears to work. I can see the BizTalk host process making connection attempts via the proxy but it doesn't seem to work.

<system.net>  
    <defaultProxy useDefaultCredentials="true">   
      <proxy bypassonlocal="True" usesystemdefault="True"/>   
    </defaultProxy>  
</system.net>

And

<system.net>
  <defaultProxy useDefaultCredentials="true">
     <proxy bypassonlocal="True" proxyaddress="yourproxy" />
  </defaultProxy>
</system.net>

http://social.technet.microsoft.com/wiki/contents/articles/troubleshooting-connectivity-issues-in-the-windows-azure-appfabric-service-bus.aspx

Nikolai Blackie Adaptiv Integration