[SOLVED] Using Shorewall to forward all email traffic to specific server
We purchased another company that has their own domain and email server (Exchange). The server sits inside our network now but I need to accept email traffic for their domain through my firewall and forward it to an internal email server for a few weeks while we transition users off of that server. Essentially I need to run a second email server inside our network EXCEPT that this particular email server will only be getting traffic from 5 specific IP addresses since they use a service to filter their email.
Is it wise to allow all traffic from those specific IP addresses through and forward them to the Exchange server IP address? I know the company and trust them. Also will my plan work? Most of all how do I configure Shorewall to do this forwarding? Thanks in advance.