I have tried to install the SMTP proxy on the same machine as my existing exchange server.
I changed the SMTP port of the existing server on 192.168.10.1 to 2525
I created new IP address 192.168.10.3 and bind the SMTP proxy to that
I forward Firewall SMTP port 25 to 192.168.10.3
I configure the SMTP Proxy to use real server IP 192.168.10.1 and real port 2525
All seems to be working fine if and only if I allow anonymous SMTP access to the exchange.
The moment I switch to anonymous access, the diagnostics complains about the open relay, and suggests denying relay from the proxy IP. When I configure Exchange to deny relay from that IP, the diagnostics still lists that my relay in open, and a simple spam test from a non existing domain confirms that.
How can I close down the open relay? Without having to switch to just authenticated access.
If I were to use authetication, how do I authenticate the proxy?
Thanks in advance,