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Exchange 2010 migration to office 365 with active directory synchronization

    Question

  • We have Exchange 2010 on-premises for our organization emails. Now we plan to migrate to Office365. The plan is to migrate all the mailboxes to cloud while keeping Active directory synchronization enabled (The  on-premises setup will be remove).

    Hybrid deployment should be used if both on-premises and cloud bases servers will be used so Cutover Exchange Migration suites for this operation. But the tutorials I have gone through say that Cutover Exchange Migration will fail if Active directory is synchronized before the migration.

    My questions are

    1: While migrating from Exchange 2010 to Office365, can we sync the active directory after the migration? Will we be able to manage users created by Cutover migration process?

    2: Can we use Hybrid Deployment in this scenario and then remove our on-premises exchange server?

    Friday, August 24, 2012 10:57 AM

Answers

  • Thank you very much for your questions.  The reason that DirSync can't be run before the cutover process is performed is because the cutover process creates the user objects.

    1.  Once the migration is completed, you are free to use DirSync to sync your on-premises AD to Office 365.

    2.  Hybrid deployment is required for staged migration, but there is no reason you can't remove Exchange after the migration is complete.  We do recommend, however, that you keep exchange 2010 installed so that you can manage users, etc. post-transition, through an easy interface instead of having to manage everything through attribute manipulation.

    Have a great day,

    Dan


    http://insecurityinc.info

    Tuesday, August 28, 2012 8:20 PM

All replies

  • Thank you very much for your questions.  The reason that DirSync can't be run before the cutover process is performed is because the cutover process creates the user objects.

    1.  Once the migration is completed, you are free to use DirSync to sync your on-premises AD to Office 365.

    2.  Hybrid deployment is required for staged migration, but there is no reason you can't remove Exchange after the migration is complete.  We do recommend, however, that you keep exchange 2010 installed so that you can manage users, etc. post-transition, through an easy interface instead of having to manage everything through attribute manipulation.

    Have a great day,

    Dan


    http://insecurityinc.info

    Tuesday, August 28, 2012 8:20 PM
  • Dan - im interested in your comment:

    "We do recommend, however, that you keep exchange 2010 installed so that you can manage users, etc. post-transition, through an easy interface instead of having to manage everything through attribute manipulation."

    What does this mean exactly - I am planning a Exchange 2010 > Office365 project with a view to completely decommissioing 2 exchange organisations!
    http://social.technet.microsoft.com/Forums/en-US/onlineservicesmigrationandcoexistence/thread/15f2c7e8-5743-4991-ac18-0af8f23a9d30

    Would appreciate your input..

    Regards

    Nathan

    Monday, January 28, 2013 3:06 PM
  • Hi Nathan 

    Did you ever resolve this issue? Did you end up having an Exchange server on ground also for the user admin? I am not a technician but I am trying to understand what this is all about. We were told that this extra Exchange server is for creating users with the attributes that are necessary by Office 365 before it recognizes the user as an object that can be mailbox enabled.  

    We are presently exploring different possibilities:

    1. An exchange server on premise (rather expensive, as all our servers are hosted)

    2. Scripting to get the necessary AD attributes: (mail; targetAddress; proxyAddress)

    3. Deploying ADFS/ADFS proxy in Windows Azure

    It's quite frustrating that we wanted to bring down our cost by moving to the cloud, and now it turns out that beyond exchange in the cloud we still need an exchange server as well as an ADFS and ADFS proxy in order to get the same functionality as when we just had the Exchange on premise.

    Thursday, April 18, 2013 5:08 PM
  • Sorry Peter -  we dropped all o365 plans due to us having 2 separate domains/AD and it not being possible to make the switch smoothly.
    Tuesday, April 30, 2013 3:57 PM
  • I understand that you'd want/recommend to keep the Exchange 2010 server in place for management of the objects etc.. which I would fully agree with, however depending on the level of customisations you need to do ADModify might be a good replacement tool. This tool modifies single user or multiple user attributes. I use if for implementations where there is no Exchange 2010 server in place, its a great tool for adding or removing multiple SMTP addresses to all Users in the Exchange Org and also modifying things like the UPN for all users and so on. worth a look at if you need some sort of on premise user management for certain attributes.

    The only thing it cannot manage locally is the transport rules etc...

    Monday, May 20, 2013 9:29 AM