Error Port 25: Email received but not send

NethServer Version: 7.9.2009
Module: E-mail

Hi, i have installed Nethserver with E-mail module on a VM: i’ve a DMZ set from the router to the VM, but when try to check the port 25 from Domain he say block. What could i do?

Could it be that your internet provider is blocking port 25 actively? If that is the case, you should use the smart host of your provider for sending email


Thanks for the reply, i have Iliad at my home and already requested and verified the static ip only for me. If i test with telnet:

Schermata del 2022-12-06 10-18-02

So i think that my email server could reach the 25 port or am i wrong? I’ve tested the send between account of the same domain on the Nethserver and the flow is ok, but if i’ll try to send outside (like Gmail or any other external domain) the mail remain in queue. :joy:

My question was about fastweb because it was announced from the ISP that port 25 would be closed as default (asked for opening if necessary).
AFAIK Iliad do not provide full 65k TCP and UDP ports, but a smaller subset (which i don’t remember if they were 16k or 32k).
Unless you’re paying for static address AND full TCP/UDP ports set. I don’t know if currently Iliad provide this kind of service and as business contracts for Internet.

I’ve already asked at Iliad a single static public IP for my connection and before i was in the first stack of the ports given (1-16k). But if the telnet command say ok why i don’t send email?

Here is a similar discussion (sorry but it’s in Italian):

Long story short. Problem is ISP, not NethServer.

Sorry for the late reply but as pike mentioned above Iliad in Italy block the outbound connection for port 25: suggestion on how to solve this? How to modify the port 25 in another one without the use of a smarthost?

  • Change ISP
  • Give up to have internal mail server
  • Buy VPS
  • Buy hosted server
1 Like

I will try one of these,thanks!