A Forum reader recently asked:
“I have a server beween my GWIA (7.0.2) and the Internet that does anti-virus/anti-spam. How do I restrict GWIA so that it only accepts SMTP from this server instead of from wide-open sources?”
And here is the response from Bob Mahar …
– On NetWare: Enable IP filter support in INETCFG and filter SMTP access except for the allowed address.
– On Windows: Enable the firewall and allow SMTP from the allowed address.
– On Linux: Use IPchains or whatever from the allowed address.
You get the idea. Or, you could use a real firewall upstream as well.