We are currently not receiving email from external sources.
Up until Tuesday it was working well. Since then the only thing that has changed is the IP address of our Netscreen firewall.
It used to have an internal address of 10.1.0.254/16 and was local in my server room. We changed recently to an MPLS solution and now the firewall is in our ISP's data centre with an address of 10.44.92.120/16.
The public facing IP is the same on the new firewall and the policies are a direct copy from the old firewall.
Is there somewhere in my exchange server to specify where email is received from on the internal LAN?