I have a problem with my newly setup Exchange environment for our hosted customers.

First off, when configuring the outlook client, it gives a certificate warning although the certificate has been bought and setup.

I am using a setup like this:
autodiscover.CUSTOMERDOMAIN.TLD CNAME autodiscover.exchange.COMPANYDOMAIN.TLD
(Companydomain is our company that hosts the exchange servers, customerdomain being the customers domain)

Shouldn't that work? I know that Microsoft does something like that for Office365, but I really don't think they buy a certificate for every customer..

So I guess some redirection should be setup somehow - any guidance?

Next thing: When we accept that error, and move on to actually starting Outlook, it states that the certificate is not valid for the RPC proxy server exchange.COMPANYDOMAIN.TLD - this domain is not right, as that domain is not included in the certificate. I would instead like this domain to be mail.exchange.COMPANYDOMAIN.TLD

I tried to run this script setting both internal and external URL's to be the same, with no luck.

Any guidance on this one?

I am running Exchange 2010 SP2, with CAS, HT and MBX split up on 3 different servers.