I don't know what your original question was, but it might be useful for you to explain what exactly, you are trying to acheive - there's always more than one way to skin a rabbit.
I use a domain name alias DOMAIN1.ORG for domain DOMAIN2.ORG on WIN5. The DOMAIN1.ORG Mail Domain Alias is set to on, but I can't use the control panel's MAil Manager as it doesn't show up as a Mail domain for DOMAIN1.ORG.
The question is thus how can I use the Mail Manager with the DOMAIN1.ORG domain alias without changing its current status as alias for DOMAIN2.ORG (ie DOMAIN1.ORG needs to point to DOMAIN2.ORG as I use code to change the templates served by one backend).
eko, the way HSphere works, what you are looking for wouldn't be possible. What I'd recommend is create a full domain to get mail functionality or edit its DNS records to point an MX record to somewhere else
I really don't see any explanation our team could have given you, do you think?