I am at the end of my rope. My ISP is threatening action if I don’t tighten up my SMTP security.
I run E2K behind a firewall to manage my email. Our Static IP is W.X.Y.Z, and we run a 192.168.0.X subnet. The E2K machine is 192.168.0.2, the router is 192.168.0.1.
I initially set it up like this:
-SMTP on port 25
-SMTP connector forwards all mail through my ISP’s Smart host.
-Authentication: Anon and Basic
-Connection: All OK
-Relay: Everyone.
Of course, this was insecure. So I changed the Relay to include ONLY the subnet.
When I did this, ALL MAIL FROM THE INTERNET was bounced. The bounced mail included a line that said “Server cannot Relay for W.X.Y.Z”.
So I included W.X.Y.Z in the resources that can Relay, and I had the same problem.
My server is acting like this: If I shut of Relaying abilities, it will not accept incoming mail from the internet.
Is that correct?
Why does this happen? What does Relaying have to do with accepting mail destined for my server?
I have heard of solutions that include 2 SMTP servers- one internal to Relay mail out and one to accept messages inbound. But again, if the inbound server has to have relaying available, how do I prevent it from Relaying for people outside my subnet?
HELP!