My Virtualmin Pro system has been functioning perfectly as an SMTP intermediary that provides spam/virus scanning and outgoing SMTP services. Our actual internet email services are an external third party which I use fetchmail to pick up all our internet email and scan. I know, it's a strange git-up but I'm forced to do things this way at the moment.
We have an Exchange 2000 server for internal use. Currently our users use Microsoft Outlook for both servers. The postfix SMTP server is polled by each Outlook client for it's incoming email and Outlook uses postfix to send outgoing email.
What I want to do now is to have postfix on the Virtualmin Pro box to forward (relay?) incoming internet email directly to the exchange server. Also to setup the postfix server to act as a smarthost for the exchange servers outgoing SMTP mail.
I think this is do-able. But, I need some assistance/knowledge on exactly how to reconfigure the postfix server (and procmail?) to act as an incoming relay for the exchange server and as an outgoing smarthost. Nothing stored on the Virtualmin Pro box.