Mailing List Message #92625
From: JGR Help Desk <>
Subject: Restricting SMTP Access
Date: Mon, 17 Sep 2007 06:10:40 -0700
To: <CGatePro>
X-Mailer: Apple Mail (2.752.3)
Hi There!

My client is running a Communigate Mail server version 4.1.8. I am looking into upgrading them but for the time being I need to solve this issue.

I want to restrict SMTP access to two groups. 

1. Email account users who authenticate using their mail clients.
2. A list of client IP's that include internal devices and our externally hosted spam filter solution (frontbridge)

I've added the client IP's to the client IP list and I've tried setting SMTP to force authentication for "non-clients". I've even tried forcing authentication for "everybody" but no matter what I try, I can log into port 25 via telnet and send a message to a local user account pretending to be any domain and email address that I so desire. 

Even if the domain from my offsite location were valid, I still don't want SMTP servers sending mail directly to my mail server without authenticating. The only SMTP traffic that should be hitting my mail server without authentication should be from the IP's that I provide but that is not happening. 

I've looked for HOURS, searched the web, read through the manual and I'm really frustrated. Any help that anyone could provide would be greatly appreciated.

Thank you for your time,
James L. McMahan Jr.

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