I have a mac server but my question has long left the realm of the GUI. My last hope is a unix forum. 

I have a cisco router with two WAN ports. The mac uses postfix 2.8.3. I have correctly configured the port forwarding for in this case port 25. When I however try to open a telnet session from an external host to the IP addresses of my WAN ports using port 25, I only get a postfix reply on WAN1. WAN2 gives me an "Unable to connect to remote host: Connection time out". If I however have WireShark running I can see that the router forwards the request, but postfix just doesn't seem to "pick up".

I reviewed my main.cf and there was nothing that suggested that postfix should be picky which WAN it wants to use. inet\_protocols is set to all and I even tried adding the static ip addresses of each of my WAN ports to the my networks variable. 

I can't seem to get it to work though - does anyone have any tips where I can look next?

Thanks