I'm having a big problem! I have a new ISA Server with 2 network cards: (a) have public IP (all ips from /28 class C), (b) have 10.11.0.26. My default gateway from (a) use as default GW my router. The router and ISA as connected with a cross-cable. The DNS from (a) as designed from my ISP. At network (b), i dont have default GW and the DNS Servers are my DCs. Wen i publish a SMTP Server, i select 1 valid IP and select my internal Exchange Server. After it, from the internet, wen i make a telnet on port 25 to that valid ip, i dont receive any message from Exchange Server. From the ISA Machine, i make a telnet to internal address (10.x) and it works fine! Does n1 know what is happing? Thanks!!! Rafael Rodrigues.