How to set-up autoreply on mail alias of an alias domain?

Ubuntu 20.04.4
Virtualmin 7.0-4

Hi all,

I am using Virtualmin for about 4 weeks now, really love it!

Here is my situation:
Client has domain-A. com as main domain. domain-B. com (old company name), is an alias virtual server of domain-A. com.

Mail for info@domain-A. com is being forwarded to person@mailcompany. com (It’s a special mail cluster the company has to use due to sensitive data).

info@domain-A. com is an alias that forwards to person@mailcompany. com.
domain-B. com aliases is set-up so it takes over the aliases of domain-A. com (Copy aliases from target).

Now the question is: How to set-up an auto-reply only on info@domain-B. com?

Hope you guys understand the situation.
Thanks in advance!

With kind regard,
Treecamp