at first this is what I thought the solution would be, but Mark Wells said that his mail server is on the same subnet as the client machine (192.168.1.8 and 192.168.1.34)... so why can't the mail server communicate directly with the client machine? so packet go from client to firewall and are redirected to the mail server.. then the mail server will arp for 192.168.1.34 and return packet directly to him). is this not possible?
No, this is not possible because the client will think that it is talking to the firewall and is getting a response back from the mail server which it was not talking to (in the client's mind).
Grant. . . .
