I have managed to setup the exchange 2007 server (single) and configured our ISA 2006 server accordingly, but emails and not getting through. It appears we can send internally and externally ok, but we can not receive. Our mx records have been modified accordingly. Not quiet sure what we are doing wrong.
Exchange 2007 sp1 (single server)
ISA 2006 Ent
ISA email publishing rule
1: Smtp outbound, from exchange server to External isa interface
2: Smtp inbound, from anywhere to exchange server (listening on external isa interface)
MX record - External ISA ip address