Hello @mughal
There is already a feature request that covers “parts” of this request.
→ Webmail on Custom Domain - #18 by Andre
Therefore, I would alter this request for the DNS settings.
Aside from that, there is the possibility to have your own servers on Plesk or cPanel with the Sitejet Builder. You would be able to set everything up as you wish without “Sitehub”.
For more information, take a look here: 