I am trying to complete configuration of RPC over RPC. I have it mostly working, the Mail and Public Folders types show HTTPS. However, the Directory does not connect via HTTPS - on the internet it just never connects, on the LAN it fails over to TCP/IP. This seems to only affect the speed of the initial connection to the RPC Proxy when on the internet - it can take several minutes to connect the first time, but thereafter all functions seem to work.
Our setup is one Exchange 2003 FE OWA server in the DMZ, one Exchange 2003 BE server in the LAN hosting mailboxes, and two Windows 2003 DCs in the LAN - both GCs. We are using a cert from GoDaddy. In the course of trying to get this working I have implemented registry changes on the GCs and both Exchange servers to specify the ports as shown in several frequently linked guides (Sembee's being one of them). The firewall has now been configured to allow all traffic from the FE/OWA box to both the BE and the GCs, though I would rather limit the open ports if possible.