The purpose of this server is to host email for domains other than the domain the server resides on, and to replace an existing Zimbra installation that has been working fine(mostly).
The Carbonio server is named mail2.domain.com.
There is another mail server that serves this domain named mail.domain.com
The installation of Carbonio seems to have gone fine. Hostname lookups both local and private all seem to be in alignment "mail2.domain.com". Even the LE certificate worked just fine. From Carbonio webmail I can send a message to zextras@domain.com and it gets delivered to the Carbonio inbox. I can reply to that message it the reply is sent normally. I can even send email to outside domains.
My confusion is that after final setup, the 'domain' present in Carbonio became "domain.com", rather than "mail2.domain.com". As such, the admin user account became 'zextras@domain.com'...but domain.com email is handled by the other server I mentioned. For example, email sent from the outside to the account on Carbonio 'zextras@domain' are delivered to the server mail.domain.com, because that's who handles email for this domain. Only notifications generated local to the server are delivered to the inbox.
So..the domain listed in Carbonio is domain.com. The Public Service Host Name is mail2.domain.com, and I have added a virtual host named mail2.domain.com (to replace the one that was auto-created - domain.com)
How can I configure this server in a way that it does not think it is the mail server for 'domain.com'? I was expecting, I guess, that the new domain within a fresh install of Carbonio would have been "mail2.domain.com" - or am I way off in my thinking?
Thanks for any tips...