Document information

Document ID: 4652
Subject: Diagnostic test fails for open relay
Creation date: 12/14/15 4:35 PM
Last modified on: 1/18/22 10:05 AM

Open relay test fails

Xeams includes a built-in diagnostic test method that runs several tests related to your configuration. Often it complains that your server is configured as an open relay. OpenRelay.jpg

This page describes why this happens and what can you do to avoid it.


Assume you have configured Xeams to be a firewall between your actual Email server, such as MS Exchange, and the Internet. Incoming emails are first received by Xeams and are then forwarded to your actual email server.

Assume you are also using the SMTP Proxy server in Xeams for incoming emails.

Problem description

When you use the SMTP Proxy server in Xeams, the actual user and domain authentication is done by your actual server. Meaning when an incoming message comes for, it's your actual SMTP server that checks if it can accept email for this user.

The actual SMTP server (last one in the picture on the left) also thinks that the email is coming from the IP address where Xeams is running. It is no idea that there is a Proxy server in the middle.


You must configure your actual SMTP server, such MS Exchange, NOT to accept relay from the IP address where Xeams is running. Since every email received by your actual SMTP server appears to have come from Xeams, allowing relaying from this IP address opens up your email system to accept relayed messages from the Internet.

Once you configure your actual email server NOT to accept relayed messages, the diagnostic tests should run fine.

User comments

Posted by nusul on 8/2/14 6:59 PM

You save my day! I think, this must be put on the relay page, it's too important, and made me crazy, why my exchange become relay after xeams install. And the problem is so trivial, i had the 192.168.* ip in relay, and not only the

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