Firewall/NAT

I just implemented a m0n0wall that has 5 public IP addresses.  One is configured as the WAN IP, the others are in my Server NAT.  I have configured all of my NAT & Firewall rules as needed, and these work just fine.  The problem is, I cannot use 1:1 NAT because multiple servers provide the same service (Such as Terminal Services), and m0n0wall wouldn't let me create the rules thereby.  So, using Server NAT allowed me to create the necessary inbound rules, but when you go to whatismyip.com from any server, they do not return the public IP I'd like to show, they all return the m0n0wall public IP.  For example, these are my IP NATs....
.233 = m0n0wall WAN IP
.234 = exchange server
.235 = accounting server
.236 = POS system server
.237 is currently unused
How can we make it so that the world sees traffic coming from the exchange server, for example, to be coming from .234 rather than .233 ?
Any help is greatly appreciated.
Thanks,
Matt

You need to configure Outbound NAT rules accordingly, and enable manual outbound NAT.