Hi, In Tom's notes it mentions you need to add the following entries to your clients host file: 192.168.1.70 owa.msfirewall.org 192.168.1.70 exchange2003be.msfirewall.org The IP's he is using are the IP addresses on his ISA External NIC. My question is if I am using say a Router to connect to the net which has a static IP assigned to it, and all the traffic is being forwarded to ISA from this router, do I use the internet IP or do I use the external LAN IP address on ISA? Toms example of 192.xxx.xxx.xxx is a LAN class IP so it can be confusing. ;) Thanks Andrew