I just installed Mail-in-a-box in a test site. I installed it as box.mydomain.com and I noticed in the admin site that it’s configured to serve the domain root (mydomain.com) as static files from a folder on the disk. I already have a site at the domain root on a different server - is it possible to not do this? Or do I have to move the other site to a different sub-domain?
Sorry, I just found this - Installing Mail-in-a-Box on a subdomain.
In the Admin area on the Custom DNS page you simply add an A record for the root domain (and www if it is used) pointing to the IP address of the other server.