hardware/mailserver - Host Multiple Domain

If you have experience on hosting multiple domain in same server using hardware/mailserver docker image please share.

My goal is to host 3 different domain with their email:

domain1.com.my domain2.com.my domain3.com.my

domain1.com.my - is the primary domain. but other domain should have their mail server too, including Lets Encrypt SSL.

Thanks in advance.