OT Routing Question

[Thom Paine]

I have a question that's not really to do with Fedora, but with routing.

I have a private IP network 192.168.142.x with a machine behind the
cicso firewall 142.142.142.x and I want that machine to be able to talk
to the mail server sitting on 192.168.142.25.

Is there a way to do this without using two network cards or changing
the gateway?

I thought I could add a route statement, but I'm at a loss.

thanks.

-=/>Thom