Mailbox names complicated

Hi everyone. I’m completely new to webmin/virtualmin and even new to system administration on Linux, so sorry for stupid question. I have 3 domains which let’s say names of them are, and When I set up webmin, I used my main as fully qualified domain name. Then I created 2 virtual servers and Now I have user named “admin” so I have, but I also want and How can I use fully functional mailbox instead of alias? I’m ready to remove everything and start from start. Just show me the way please

I don’t understand what you mean by “instead of alias”? Just create a mailbox for each of your admin accounts in the right domain. Virtualmin will create an admin.test2 and admin.test3 account for you. They are all independent accounts with independent mailboxes and logins. They are not aliases, unless you created them as aliases.