With the release of Exchange Server 2010 SP2 later this year, we will add a new feature known as Address Book Policies. Following this addition, hosters who wish to deploy the standard on-premises configuration of Exchange and use ABP will be supported.

As you may have read in a recent post over on the Exchange Partner Marketing blog, our view on whether to host Exchange using Hosting Mode
or the standard on-premises configuration is changing in response to
feedback we’ve had from both hosters and customers. We recognize that
the Hosting Mode configuration of Exchange we released as part of SP1
provides a more robust multi-tenant solution, but lacks some of the features
available in the standard on-premises configuration. Many of these are
key features which customers are asking for, like Exchange Unified
Messaging. We want to enable our hosting partners to offer the same rich
feature set that our on-premises customers are used to. As such, with
the release of SP2 for Exchange Server 2010, we intend to broaden our
support stance to include hosting the on-premises configuration of
Exchange in a multi-tenant environment.

To be eligible for
support, hosters will need to adhere to a few configuration guidelines; a
framework we will publish in conjunction with SP2. The framework will
outline the configuration challenges of hosting Exchange in a
multi-tenant environment which need to be solved, and provide general
direction for developing solutions in the most supportable way. Let’s
consider a couple of examples:

• As I
  mentioned earlier, the Address Book Policy feature is a key reason that
  we will be able to support hosters using the on-premises configuration
  if they are using SP2. The framework will specify that directory
  segmentation should be done using Address Book Policies, not by a series
  of Allow/Deny ACE’s on Address List objects.
• For
  provisioning, the framework will specify that the creation of objects
  (such as a tenant organization or a mailbox) in Active Directory and
  Exchange should use our standard built-in tools, PowerShell cmdlets, and
  documented APIs. Code should not be written to create objects directly in Active Directory or Exchange, bypassing these standard tools.

An
automation vendor or a hoster, should they choose to, will be able to
build their own automation tools using this framework. The easiest and
quickest route to support for most hosters, though, will likely be
through engaging with a hosting automation vendor whose solution adheres
to the guidelines. In order to help service providers quickly find the
right automation software, in the SP2 timeframe we will publish a list
of solutions which follow the framework (and thus are eligible for
support). These solutions will be validated by Microsoft in much the
same way that we currently validate load balancing solutions.
I’ll hasten to add that this will not be a formal certification
process, but instead will be an assurance to our customers that we have
worked with the vendor and are satisfied that it conforms to the
framework.

So, what does this mean for you today
if you want to use the on-premises configuration of Exchange to host
mailboxes for your customers in a multi-tenant environment?

• If
  you need to deploy prior to SP2, we recommend that you work with an
  automation vendor and use their solution. Your vendor of choice will be
  your only source of support. Your vendor will hopefully have plans to
  update their solution for SP2 per the soon-to-be-published framework, at
  which time you will have a path to being supported by Microsoft once
  you’ve upgraded your infrastructure.
• If you plan to deploy
  post SP2, and you intend to use an automation solution from an
  automation vendor, you should ensure your chosen vendor is working with
  us to validate their solution and deploy when that solution is ready.
• If
  you plan on building your own solution using the standard on-premises
  configuration of Exchange, you should consider waiting for SP2 to ship
  and then develop your solution following the framework to ensure you
  receive the best level of support from Microsoft.

We hope
this announcement is good news for those hosting Exchange, as it
provides you with more options in your deployment and will help you
obtain support when you need it.

We look forward to hearing your feedback and as you know, we do act on it.

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