UNIX and Linux Applications

So what should I do?

Send email fome my google acount to user@wi.zut.edu.pl?

No,

you must find out, why you send to zimbra.wi.zut.edu.pl and give me the comlete Rejectmessage so I can see why the host zimbra.wi.zut.edu.pl reject your mail.

But I think you should first learn about more about postfix and the smtp protocol to understand what you are doing.

Regards,
xabbu

Maybe I'm stupid, but I don't get it

Budrys,

first specify exactly what you want to do with your Mailserver.
Maybe then I can help you to set up correctly.

Regards,
xabbu

I want to set up it correctly.

If it is possible to send mails from users and to my users.
Then I need to install antispam and antivirus.
And connect it with RoundCube ( to have access to mailboxes)

---------- Post updated at 05:27 AM ---------- Previous update was at 05:26 AM ----------

Mayby we can use other mail system

Budrys,
I need more infomations for that.
Where are your users? Local in your company? Will you send mails from locally users to external users?
The problem is not the mailsystem the problem is your understanding how all this works together.

I'll try to help you but you need to know what you exactly want.
For a correct setup of any mailsystem the DNS is mandantory If you are unable to set the DNS correct your can't use the mailsystem for external use.
And you must know your network infrastructure.

Regards,
xabbu

As I told You I have VM on univerity network.
Users are on my machine server.

Could we configure that mail system only for internal use?