Exchange 2010 SP1 has built-in multi-tenant support, which helps service providers to host multiple organizations in a single Active Directory environment. There are few features which are available only in hosting mode and few others which are not available, compared to a normal deployment of Exchange 2010 SP1. 2010 SP1 will form part of the suite of multi-tenant capable products that will replace the Hosted Messaging and Collaboration solution.
Few points to note about installing 2010 SP1 in hosting mode:
- The installation can only be done in command line.
- You need to use /InstallWindowsComponents while running the setup to install all windows components required for Exchange. This will not install the pre-requirements only the windows components! Always install the pre-requirements first.
- You need to use /Hosting switch while running the setup to install Exchange in hosting mode.
- 2010 SP1 is required.
- Exchange Management Console will not be installed.
Exchange 2010 SP1 doesn’t support the following features in Hosting mode (from Technet):
- Exchange Management Console
- Public Folders
- Unified Messaging Server role
- GalSync
- Federation
- Business-to-Business features such as cross-premises message tracking and calendar sharing
- IRM
- Outlook 2003 support (EnableLegacyOutlook)
- Edge Transport Server role
- Same forest upgrade from Exchange 2007
- Resource forest
- Parent-child domains
- Discontiguous namespace
- Disjoint namespace
Here is based on the blogs zerohoursleep and howexchangeworks how its done! This step-by-step tutorial that will guide you to installing your first Exchange 2010 SP1 multi-tenant organization to a fully operational mode.
Lab setup
For this lab I am using 2 servers running Microsoft Windows 2008 R2 one of them acting as a domain controller for the lab domain lab.com and the other will be running all roles of Microsoft Exchange 2010 SP1 CAS,HUB and Mailbox.
Of course in a live environment exchange roles will be most probably split among multiple servers but the concept is pretty much the same.
I will assume that the Domain Controller is already installed and that the exchange server to be has already Windows 2008 R2 installed with all the required patches to deploy Exchange 2010 SP1.
Installing Exchange 2010 SP1 in hosting (or multi-tenant) mode
Installing Exchange prerequisites on Windows 2008R2
I am used to this script to automate installation of the prerequisites since I find it very clean.
We will start by running the powershell administrator “right click -> run as administrator” and allow the script execution using
Set-ExecutionPolicy unrestricted
Running the script will then offer you a menu, in my case I need to select option 6 since all roles will be installed on the same server and restart the machine after.
Installing Exchange
As you may already know Exchange 2010 multi-tenant can only be installed using the command line by adding the /hosting parameter, we will initiate the installation by running
setup.com /m:install /r:m,ca,ht /installwindowscomponents /hosting /on:ExchLab
Let me first explain the above command
- /m stands for /mode and we are running the installation mode
- /r stands for /roles and we want to install the m (mailbox) ca (client access) ht (hub transport) roles. Of course you will need to change this if you don’t want to install all roles
- /hosting is required to tell the setup to run the hosting installation
- /on stands for /OrganizationName and you will define here the name of your Exchange organization. I called mine ExchLab
We will now wait for the installation to finish


A few differences with Exchange not hosted
The first thing I have noticed after the installation is differences in Active Directory Users and Computers like the presence of a brand new Organizational Unit “Microsoft Exchange Hosted Organizations”

And the addition of new Exchange Security groups (plus the absence of the UM one)
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Now of course the absence of the Exchange Management Console should have been first however this I was expecting since it is all over the place so I was expecting this.














