How to open another port?

[b1bb2]

It looks like my old post disappeared. Search profile posts says I am not found. So I am starting a new post.

I have VPS with fresh install of debian 11. I have open port: 22 Secure Shell (SSH). I have closed port: 25 Simple Mail Transfer Protocol (SMTP). I am trying to open port 25. I am not try to change the port numbers, I am simply trying to open one more port. As one port is open and the rest are closed, I guess that a firewall is installed and running. Or what else can cause this? And how to fix this?

 

[johnb35]

You mean this thread?

exim email server

I would like to use the exim program in debian to be my email server on VPS. I do not wish to get domain name until I understand things better. To start simple, I installed package exim4. Now, what settings should I change? Please help. It seems the configuration files are in /etc/exim4/conf.d/...

www.computerforum.com

 

[beers]

Is your running daemon even bound to the port? There's no such thing as like 'an open port to a process that doesn't exist'.

 

[b1bb2]

Yes, thank you johnb35. I could not find it because it is in General Software. Search profile posts did not find it. How can I find my posts? And now it is a little outdated. I might go back to it later. My new post is OK with me. It is current and specific. If it will help, I can detail all the things I tried.

 

[johnb35]

Search profile posts did not find it. How can I find my posts?

Your profile posts are exactly that, profile posts. Your forum posts you can find by seeing the attached image. click on your username and you'll see a page similar to this minus a few things. Look at the find box I have opened.

 

[b1bb2]

Thank you johnb35.
To beers: I guess running daemon means a process like firewall. I can not find the running daemon that is causing this problem. If I do find it, then I can check if it is bound to the port (whatever that means.) Sorry I am new to these terms. It sounds like you are asking about one of these: /etc/services, netstat, ss, lsof. Can you give me more details of how to check?