Domain Check Status Port 25 Failing

Current Production Nethserver 6.10
Testing Replacement Nethserver 7.9.2009


Our current Nethserver is configured to act as an Anti-Spam/Anti-Virus gateway to our Exchange Server. All mail filtered on the server is relayed to our Exchange Server.

Both Nethservers, production and test, and the Exchange server are in the same network. There are no firewall restrictions and the Exchange server is configured to accept mail from both Nethservers.

The relay is working flawlessly with the current Nethserver 6.10.

For NethServer 7.9.2009, after installing and updating, the “SMTP Proxy” package was installed. The “Email” package was not installed.

Our two email domains were added and both were configured with the Exchange Server as the “Destination Server” to relay the mail.

When performing a “Check Status” for both domains, it indicates that Port 25 is unreachable.

From the Nethserver, I can telnet to the Exchange on port 25.

Any assistance would be greatly appreciated.


Dominic Insogna

May I ask if you have only 1 public ip address?

We have multiple public IP addresses.

The Nethserver in testing has not yet been configured to be publicly accessible on port 25.

Can somebody help him

Probably because the Nethsecurity is not reachable via public IP

Thanks for the reply.

If I understand correctly, the “Check Status” only tests if the server is reachable publicly on port 25 and not if it can relay to the destination server on port 25 when configured to relay mail.

I configured the domains to relay to another server and was under the impression that the “Check Status” was testing the relay on port 25. I guess that is not the case.

the port 25 check basically does this:

curl --silent --fail --max-time 5

So yes it only checks if port 25 of the nethserver is reachable from the public side.

Hi Dominic,

This is just a cosmetic problem that I have here as well. I have multiple static public IP’s. One of them is reserved for the mail function, while another one accepts requests for Nextcloud and Webtop. But the Nethserver itself reports to the WWW with a third IP, but the MX is not registered to it. That’s why I regularly see the red cross during the query.

Regards Uwe