How to limit iredmail to one domain?

Question

Nginx

Good day,
The situation is this, I installed Iredmail on a clean server, while everything was configured to the look I needed, it dawned on me that the system ate my domain, although I fed it a subdomain. Now this is what happens:
-> mydomain.com - immediately redirect to mydomain.com/mail
-> mail.mydomain.com - immediately redirect to mail.mydomain.com/mail
all virtual hosts that I tried to configure in nginx - also a redirect - > domain/mail .
How to configure/restrict it correctly - in order for something to be loaded only on a subdomain of the type - mail.domain.com, and gave me the opportunity to deploy new hosts on the server?
And yet, is it okay to keep both nginx (iredmail running on it) and apache on the server together?