Question : hosting multiple businesses with one exchange server 2007

hi,
our organization is divided into two entitites. One is on-site, the other business accesses the office remotely via site-to-site vpn.  rather than buy two seperate servers, 2 exchange 2007s, etc.... can we have seperated exchange (i.e global contact list, address books, etc...) on one server? i read somewhere that all you need to do is have seperate storage groups, but is that really the solution? As a second option, we have vmware, should i virtualize another DC, have a seperate domain, and use exchange with the entire forest? What is the best policy here?

Thanks,
Brian

Answer : hosting multiple businesses with one exchange server 2007

Putting additional domain controllers in will achieve nothing. Exchange can only serve one forest and all users will appear in the GAL. If you want to use one Exchange server but you want to separate the users then you must use the above technique.

Simon.