OK, guys, I've noticed a lot of good guides out there, but I really would like it if we could explain in detail how to set up our untangle servers in the following configuration
Internet > Firewall (3rd party, not the untangle filter) > DMZ (Untangle) > LAN
That is, the Untangle Box sits in the DMZ, and acts as the barrier between the LAN and the DMZ. The Untangle server needs to forward e-mail to a server that sits on the LAN. The untangle serves internet to LAN computers, not DMZ computers.