After you successfully migrated all mailboxes from on-premises Exchange organization to Microsoft Office 365, ensured that all users can connect to their cloud mailboxes, and mail flow is established properly, you may start decommissioning your on-premises Exchange servers. Refer to Microsoft documentation for information on how to do that.
For information on how to decommission existing Exchange servers, go to http://technet.microsoft.com/en-us/library/cc463439(v=ws.10).aspx.
Establishing co-existence of objects between Active Directory domain and Microsoft Office 365 using Migration Manager for Active Directory is supported only during calendar synchronization and mailbox migration. To continue synchronizing objects after you finished migrating mailboxes, consider to use the Microsoft Azure AD Connect (link) or Quest One Quick Connect solution (link).
You may also need Quest One Quick Connect for the following procedures described below:
Synchronizing Password Changes
You may synchronize password changes from Active Directory to Microsoft Office 365 using Quest One Quick Connect. For that, you will need to set up the same matching in One Quick Connect as you configured in Migration Manager for Active Directory (Microsoft Office 365) console and then set up password changes synchronization.
TIP: The most reliable way to achieve the same matching is to use users' UPN prefixes as matching criteria.
For information how to use Quest One Quick Connect, refer to its documentation.
Synchronizing Distribution List Membership
You may use One Quick Connect to synchronize users' membership in distribution lists (DLs) from Microsoft Office 365 to Active Directory. For information on how to do that, refer to Quest One Quick Connect documentation.
You can track the progress of the operations on the Statistics tab in the Migration Manager for Active Directory (Office 365) console.
Note: Tracking of public folder synchronization is not supported at this time.
To view the directory migration progress, open the Migration Manager for Active Directory (Office 365) console and see the statistics view on the Home tab in the center pane. Statistics are available at the migration and collection levels. More detailed statistics information is displayed on the Statistics tab.
To view the current statuses of specific objects in a collection, go to the Objects tab.
The objects involved in the migration can have the following statuses:
A mailbox of already migrated user is successfully switched using Migration Manager for Exchange.
Some errors occurred during object synchronization.
Directory Migration Agent is processing the object at this moment. The object might be
A mailbox was added to a collection and was not processed by Directory Migration Agent yet.
The object has not been involved in the synchronization process yet.
The object is being synchronized by Directory Migration Agent at this moment.
The object has not been matched yet and synchronization settings do not allow creating or merging not matched objects.
The object failed to be synchronized due to error. To view the error description, go to the Objects tab.
For more information about logging and dealing with possible migration problems, see Troubleshooting Migration to Office 365.