Not receiving emails Virtualmin on Ubuntu 20 with Postfix

It seems, then, your problem is not with DKIM specifically, but with Postfix (the “unable to read banner” problem).

After searching on Google for similar occurrences, I found this post where some possibilities are presented.

Port 25 not enabled on firewall from provider, IP or domain on blacklist (unlikely to create problems when receiving emails), among others.

Did you contacted your hosting provider about this?

First of all, why did you not set a proper hostname on the server?
Using the providers domain is generally not a good idea.

Secondly, how did you install Virtualmin on the server?
Because if I remember correctly you recently had a thread regarding the templates from Contabo which was not working.

Third, port 25 is not listening. That’s why you are not receiving email. Firewall?

I really don’t know anymore. Postfix is enabled, tried also the blacklist check. None of my IPs or domains are blacklisted. My provider is not blocking any ports for their severs. I can send emails without problems.

Why do you mean with not set a proper hostname on the server(I never had problems with the hostname of the provider, but I think that I will do it)? The provider installed webmin(I chosed it without LAMP) and afterwards I have installed Virtualmin.

I have checked now the port 25 with: netstat -tuplen | grep 25 and this is what I got:

tcp 0 0 127.0.0.1:783 0.0.0.0:* LISTEN 0 5253154 840696/perl

with iptables -nL | grep 25 I have:
REJECT tcp – 0.0.0.0/0 0.0.0.0/0 multiport dports 25,465,587,143,993,110,995 match-set f2b-postfix-sasl src reject-with icmp-port-unreachable
ACCEPT tcp – 0.0.0.0/0 0.0.0.0/0 tcp dpt:25 ctstate NEW,UNTRACKED
ACCEPT tcp – 0.0.0.0/0 0.0.0.0/0 tcp dpts:1025:65535 ctstate NEW,UNTRACKED

The FQDN should be a domain YOU own, not the provider.

This implies Postfix isn’t running (or at least not listening to port 25).
If you see this post, this user had a very similar problem as you using Contabo and preinstalled stuff.
Even if the didn’t install LAMP or Virtualmin, just having Webmin installed before could lead to problems and this is obviously what happened here.

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Yes, sorry, I forgot that I made some changes and it was stopped. I will start it now and run it again.

netstat -tuplen | grep 25

tcp 0 0 127.0.0.1:783 0.0.0.0:* LISTEN 0 5253154 840696/perl
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 0 6554946 1124169/master
tcp 0 0 161.97.132.177:25 0.0.0.0:* LISTEN 0 6554942 1124169/master
tcp 0 0 161.97.132.176:25 0.0.0.0:* LISTEN 0 6554838 1124169/master

I think you are right and need to start fresh once more just with Ubuntu installed. I was afraid of that. I will start backing all up .

That seems to be the best thing here.
I tried connecting to your server and it still times out.

Start with a completely fresh install, change the hostname of the server to something you own, like server1.mydomain.com and the follow the installation instructions for Virtualmin.
This will give you a lot less issues, guaranteed.

Thank you very much Paulo for taking the time and help me out. I will start fresh with the server and see what will happen.

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Thank you very much for the help. I will do that right now. I hope that this time everything will be fine, because right now it’s like Bermuda Triangle. There are untraceable problems :))

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I NEVER use a provider’s pre-built images – and I have a good provider. But images get stale very quickly. Also, you never know whether the person who built the image had his or her own ideas about how to do it. Give me a clean OS and login credentials. I’ll take it from there.

Fortunately, my provider will let me install literally whatever I want. They’ll download it and install whatever OS I ask for, or will let me provide my own ISO. They’re a good outfit.

Richard

Hi, they just needed to install Ubuntu and Webmin without LAMP or any other “extras”, that’s it. Never thought that it would cause so many problems. Lesson learned. Want to do something right? Do it yourself :)) The cliché is true.

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Hi there,

Coming with an update. I have started fresh, installed everything manually with my own hostname, own nameservers and like you said, a lot, but a lot less issues. Don’t know what they did wrong but didn’t have a problem this time, few things that I did not know, because I am new with Virtualmin but no ghost problems with ghost errors. I wish I would have done it from the beginning.
Thank you again and I wish you all Happy Holidays and a Happy New Year!

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