just apt upgrade, update and later install mc
You installed this to Ubuntu Server 18.04 LTS?
yes, as i said its my first time with my own mail server. And i just used all available guides on youtube after watching ur guide and got my problem …
Please run:
sudo mailinaboxsystem replies that host (mydomain name) is temporary unavaliable but then start mailinabox startup …
Does it report anything after it completes running?
just start up mailinabox and again said that sudo unable to resolve host mydomain.com :Resource temporary unavailable
It sounds like you have changed a file or configuration some place. What did you change on the system?
i didnt change nothing
The output of
$ hostname
box.example.com
is what you should see.
Did you set the hostname in your ISP dashboard for the server? Some ISPs may reconfigure the server hostname to match what you put there.
yes i do set my hostname in my isp dashboard for the server
Does the output of hostname match the what is in the ISP dashboard?
no, showed the old one hostname that was used for other project. But i changed my hostname in isp and in isp output hostname is mydomain.com. and reinstall OS to ubuntu 18.04
The ISP hostname should be box.example.com.
If you don’t have anything on this installation that matters, such as emails or other files, my recommendation is to reinstall the OS completely. I’m actually not sure what the problem is, but nuking from orbit is sometimes an acceptable step, as likely it’s already been more time than just reinstalling MiaB to a fresh system.
yes it is 
You are masking the actual output and telling me the hostname is mydomain.com. You need to have the subdomain box included as part of the hostname. In your words, you should have box.mydomain.com as the hostname.
yes it is my domain is box.mydomain.com … im using (mydomain) just of the privacy moments. Im sorry but i dont know about that we are in a public conversation or in private. I just dont want to show others users my domain name.I apologize for the inconvenience.
That is fine, but when seeking help you should provide the equivalent verbatim output, and mydomain.com is a different output than box.mydomain.com.
I don’t really know why sudo isn’t running as I’ve never had that problem and there are search results on fixing the problem, but you never should have experienced that problem in the first place, and that is the real problem.
Maybe a different forum member can recommend different solution, but I would opt for reinstallation of Ubuntu, assuming there is nothing on the current installation you need to keep.
ok, but can it be problem with actually my provider ? about the dnz zone and this startup problems ?