I've wrote a few post recently regarding my troubles with Hybrid Exchange and a SPLA licence :@

Here's our current situation:

  • We have an Exchange 2010 SP3 server that is set up as a hybrid with Office 365, All mailboxes have been migrated to Office 365

  • DirSync is being used synchronize users

  • MX records point directly to O365
  • SOA is on premise so all editing of users / mailboxes is done via AD

We currently pay our provider monthly via SPLA for this server that is basically used to manage AD properties and can't see how the cost justifies itself.

Question Now that all mailboxes have migrated to 365, is there any reason why we need to keep the hybrid connection?

Could anybody advice if any of the below scenarios are do-able:

Scenario 1

  1. We Add another Exchange 2010 or 2013 server whose license is paid for out right (no SPLA)
  2. Remove current 2010 exchange server (with SPLA)
  3. Continue to edit mailboxes via EMC tools with the new server

How would we remove the current server?

What licenses would we need for the 2013 server?

Do we need to re-run the hybrid wizard (we don't need to move any more mailboxes)

Scenario 2

  1. Remove Hybrid Connection

  2. Decom existing 2010 Server

  3. Use a third party AD editor to manage exchange attributes (if they still exist)

Would decommissioning the Exchange server remove AD attributes from objects

What implications would we have if we just turned off the exchange server

Scenario 3

Change the license on the current Exchange server if possible

*What licences do we need *

If you have any other suggestions, please tell me.


Here you'll find the official documentation about how and when to decommission your on-premises Exchange servers.

If you need DirSync to stay in place, then all Exchange-related attributes can't be managed in Exchange Online, and need to be managed in your local AD and then synced; doing this without an on-premises Exchange server is a royal pain, as it involves directly editing AD attributes (such as proxyaddresses) and object permissions; thus, you should keep at least one on-premises Exchange server, and the whole hybrid setup. However, this doesn't mean you have to allocate lots of hardware resources or buy Exchange CALs, because you wouldn't be actually hosting any mailbox there: just go with a single Standard-edition Exchange server with no CALs and you'll be fine.

If instead DirSync can go and you can manage Office 365 users separately from AD users, then by all means go and remove your hybrid deployment and DirSync; things will get a lot easier.

  • Thanks Massimo, we do need DirSync to stay, I have a few Q's if you don't mind answering, 1) would i be able to get rid of the hybrid connection from exchange as I have migrated all mailboxes now 2) would I be able to install a new exchange server (licence will be paid for not 'rented' off a service provider) then remove the current server that we 'rent' 3) If I decom, could I use a third party application designed for exchange to integrate with AD to administer the attributes – Z Holt Feb 10 '16 at 13:20
  • I don't know if it's possible to remove a hybrid Exchange deployment and then re-establish it, but I'd advise against trying; just set up the new server in the same AD forest, transfer all that is required as per standard Exchange move process and then remove the current one; you'll probably also have to change a connector or two. – Massimo Feb 10 '16 at 13:45
  • I personally don't know of any tool to manage Exchange-related attributes other than Exchange itself or plain low-level LDAP editors. – Massimo Feb 10 '16 at 13:46
  • Thanks Mass, I don't think i'd need to reestablish the hybrid link as we don't plan to host any mailboxes on premise again. What will need to be transferred? I've not deployed exchange servers, just administered them. – Z Holt Feb 10 '16 at 15:22
  • There are lots of documentation around, and it depends on your implementation; also, the hybrid link isn't used exclusively for mail flow, but also to actually have the two Exchanges (on-premises and online) talk together; DirSync is not enough. – Massimo Feb 10 '16 at 15:54

Why are you paying for Exchange? If you're simply using it for management and not transport or mailboxes, this is included at no cost with your Office 365 subscription.

That said, you should absolutely maintain at least a single Exchange server on prem in hybrid mode for the management console, otherwise managing things like dynamic DLs is a real pain.

  • At the moment our Exchange is hosted by a service provider, as it is hosted we pay a monthly fee to the service provider. The free hybrid license that I believe your referring to is for organisations that DO NOT have a 2010 or 2013 exchange server, which we do, Do you know if we can delete the hybrid connection between exchange server and 365 now all mailboxes have migrated or will this affect anything. Thanks – Z Holt Feb 10 '16 at 13:23
  • @ZHolt License questions are off topic here. You should ask your preferred LAR or Microsoft account team. – MDMarra Feb 10 '16 at 15:01
  • 1
    I'm not asking for licensing information, Rgds – Z Holt Feb 10 '16 at 15:20

Not the answer you're looking for? Browse other questions tagged or ask your own question.