I have a Windows NT 4 SP6a machine with three NICs; one external, two
internal, running Exchange 5.5 SP4. I recently installed a Cisco PIX
firewall, NAT'd my web server behind it; no problems, works fine. I
tried to do the same with this Exchange server, and it will not NAT
through the firewall like the web server does. The web server had the
same NIC configuration; I simply disabled the external NIC and NAT'd
one of the internal NICs. Route print results look similar on both
machines, the gateways are correct, the access-list lines on the PIX
are correct, the static routes on the PIX are correct, etc. I can't
ping any outside hosts from the Exchange server, let alone worry about
transferring mail. Any ideas?