[c-nsp] Securing Exchange 2003

[Paul Stewart]

We have a new Exchange 2003 server internally.  Our plan it to open up
this Exchange 2003 server to the public Internet so travelling employees
can access the server as if they were on our LAN. We would prefer to not
provide VPN access to these outside people, rather use the RPC over
HTTPS feature that 2003 now provides.

Has anyone done a firewall for this?  I've done some reading and it
keeps talking about using MS ISA server for a firewall... I'd like to
use an existing Cisco 3640 with firewalling and CBAC to protect it...
Just not sure on what needs to transverse the access lists and is it
really secure?

Thanks in advance,

Paul