We have a Exchange 2003 server which is accessed by corporate user in
exchange mode (RPC) in the LAN. Some of these users need to access the server
remotely by dialup to the corporate RAS server using the smart client (MS
Outlook 2003 - Exchnage mode). There is a Firewall sit in between the RAS and
the exchange server. RAS is in a DMZ network and the Exchange is in the
trusted network. What are the ports required to be open between the RAS and
the Exchange server in order to access the exchange server in a secure manner.

Please advice