I am trying to find some documentation or How to's on how to setup a Exchange 2007 server to handle two separate companies on one server and make the two companies transparent to each other (like hosting I guess, but not needing to use the MS Hosting platform). I have a great article on how to do this in Exchange 2003 from Amit Zinman on msexchange.org http://www.msexchange.org/tutorials/Shared_Hosting_Exchange_2003_Part1.html, but as it says, for Exchange 2003. Our client has just purchased Exchange 2007 and I have it up and running, but they just aquired another company and I need to make the two companies not be able to see each other in the Gals or Address books. Any ideas or tips on how to do this?

Have you found any solution jet? I'm searching exactly the same but I couldn't find anything.

Depending on how large each environment is will determine the deployment model for your situation. You can reference the following articles which cover such material. Exchange 2007 Deployment Guide http://technet.microsoft.com/en-us/library/bb125244.aspx In most scenarios for integration during a business acquisition, we'll use products such as IIFP which allow the ability for maintaining a single GAL between two Active Directory Forests. This also goes for migration and consolidations efforts. If the business requirements call for it, you can leverage the resource forest model which typically is done for real large environments and is used in hosting scenarios. - Chris

What about using HMC 4.0? Anyone run into any good docs?

Although I havent used HMC specifically, looking through various strings it first suggests being very familiar with Exchange 2007 and MOSS 2007. With that said, conceptually; its a hosting environment targeting the SMB-Midsize market space which essentially is great for the partner space or someone very entrepreneurial. It makes sense to try and reduce the TOC for a shop of that size. Thanks Sunny Admin! I havent seen any docs, but if you do you should share them. A quick explaination Ive found was on GavinGees blog: http://blogs.msdn.com/gavingee/archive/2006/10/03/Exchange-2007_2D00_-Are-you-ready-for-HMC-4_3F00_.aspx