Everybody that has hosted Exchange 2010 running using the /hosting switch knows it is a real painful experience. It is difficult to implement, it is difficult to maintain and there quite a lot of functionality missing like UM, Public Folders, the Exchange Management Console and integration with other products like Lync Server 2010 or Sharepoint Server 2010.
There has been a lot of complaints from hosters about this situation at Microsoft and Microsoft had to make a painful decision: Microsoft will no longer invest in the /hosting version of Exchange Server 2010 and it will be discontinued in the next version of Exchange Server (code name Exchange 15).
As far as I know now the upcoming Service Pack 2 of Exchange Server 2010 will fully support the /hosting switch, including upgrading from Exchange Server 2010 SP1 /hosting to SP2, but there will be no more new developments. Also future Update Rollup fixes will be fully supported if the /hosting switch is deployed.
Microsoft is working closely with implement.com as a hosting System Integrator and in the upcoming months Microsoft will provide guidance (in the form of white papers) on how to migrate from HMC4.5 to Exchange Server 2010 SP2 and how to migrate from Exchange Server 2010 SP1 /hosting to Exchange Server 2010 SP2. The interesting part is though that upgrading from HMC4.5 to Exchange 2010 SP2 is an intraforest migration, so Exchange 2010 can be integrated into an existing HMC4.5 environment. Moving from /hosting to Exchange 2010 SP1 is an intra-forest migration, but it can be back to HMC4.5, and then to Exchange 2010 SP2. Interesting developments going on there…
One important note you have to realize: Exchange 2010 SP2 is not natively multi-tenant! Address Book Policies is about multiple address lists in an Exchange organization, but this is not the same as multi-tenancy. To achieve true multi-tenancy in Exchange 2010 SP2 you have to work with a 3rd party Control Panel vendor (or wait for the guidance). But these 3rd party vendors will most likely use the Address Book Policies as part of their solution.
Microsoft is working closely with these vendors:
- Parallels Automation Microsoft Exchange Service Module
- Ensim Unify Service Provider Edition
- Cortex control panel from Citrix for delivering hosted Exchange
- Extend ASP for hosting Exchange
If you are a hoster and have deployed the /hosting version of Exchange Server 2010 than this message will be extremely painful. I know hosters that have done this and I can fully understand their frustration. But on the longer term this is the only right solution and everyone will benefit from it.
More and official information can be found on the EHLO blog.