Topic: forwarding mail to internal server

[Geoff]

Hello everyone.
Hopefully someone here can offer me some guidance.

I have a server running e-smith 4.1.2
It is our internet gateway.
It works very well and we use it as our mail server.
All mail sent to username@ourdomain.org is retrieved from the e-smith machine using webmail.  It all works well.

I have set up another server inside our LAN called blue.ourdomain.org
Any users (on our LAN) logging into blue.ourdomain.org machine are able to send mail from the blue machine to the outside world as the e-smith gateway lets it get out.

My first question:  How can I stop e-smith from letting mail from blue.ourdomain.org users getting outside of our LAN? ie. only allow mail from users on the esmith box to be sent outside to the internet.

My second question: If I decide to continue to allow mail from blue.ourdomain.org to get out to the internet how can I configure the e-smith gateway to forward any received mail in the format username@blue.ourdomain.org onto the blue internal server?
[we have one fixed IP address that our esmith box uses.  the blue server is on an internal IP address.]

would be very grateful for any guidance.
thanks.