2 servers behind a firewall 1 for mail and 1 for website

So I have two servers behind my firewall, I want one of those to run my MIAB server and the other to run my website. If I go to the MIAB custom DNS page and set an in A record to point to my other internal server would that work? pointing an in a record towards and internal ip 192.168.x.x or is there another way i can do this?

Thank you

The MIAB Custom DNS page will be for public DNS, not for dealing with internal networks behind your firewall. I would think you’d need rules on the firewall to route traffic correctly to either your MIAB or webserver.

but doesn’t MIAB use port 80/443 for webmail access? So if i forward port 80/443 to my website server instead of my MIAB server will that disable webmail?

It does use those ports for webmail. I was thinking you’d figure this out with domains, sub domains, and the NAT. But that’s beyond what I can help with.