Putting a Relay Server in the dmz

[stevenriz]

Correct me if I'm just way off, I'd like to secure part of our internal network by closing off the smtp port into the exchange server in the firewall. I thought there might be a way to put an smtp relay server in the dmz which I would grant access to the internal network smtp port of the Exchange server using Sendmail. Does anyone do this and if so, what is required and well... how do I do it? Would the relay server become a virtual ISP for the exchange server? I am trying to piece it together in my mind. Maybe I should post this in the Sendmail forum? Thanks!!

 

[zbnet]

Easy to do, and very good security.

As far as the changes on Exchange, they're the easy bit and take no time at all. The only real change is to the IMS Connections tab - in the Message Delivery section, you click the 'Forward all messages to host:' radio button (instead of DNS), and enter the name (or IP address) of the sendmail smarthost in the box. Stop and restart the IMS service, and then the IMS simply forwards all external outbound email to the smarthost for onward routing.