Migrate All Mailboxes to the Cloud with a Cutover Exchange Migration

  • Article

Applies to: Office 365 for professionals and small businesses, Office 365 for enterprises, Live@edu

Use E-mail Migration in the Exchange Control Panel to migrate all the mailboxes and corresponding mailbox data from Microsoft Exchange to your cloud-based e-mail organization. This type of migration is called a cutover migration because all on-premises mailboxes are migrated in preparation for moving your entire e-mail organization to the cloud. To migrate only some of your on-premises mailboxes, you need to perform a staged migration. For more information, see Migrate Mailboxes to the Cloud with a Staged Exchange Migration.

An organization can migrate a maximum of 1,000 Exchange 2003, Exchange 2007, or Exchange 2010 mailboxes to the cloud using a cutover Exchange migration. To migrate more than 1,000 Exchange 2003 or Exchange 2007 mailboxes, you can perform a staged Exchange migration. You can’t migrate Exchange 2010 mailboxes using a staged Exchange migration. Therefore, to migrate more than 1,000 Exchange 2010 mailboxes, you must implement a hybrid deployment. For more information, see Exchange Hybrid Deployment and Migration with Office 365.

Important

Cutover Exchange migration isn’t available for Microsoft Live@edu. Schools can install and configure Outlook Live Directory Sync (OLSync) and then use a staged Exchange migration to migrate Exchange mailboxes to the cloud.

In this topic

  • What happens during a cutover Exchange Migration
  • Before you begin
  • Step 1   Create the migration batch
  • Step 2   Configure the connection settings
    • Automatically detect connection settings with Autodiscover
    • Manually specify connection settings
  • Step 3   Name the migration batch
  • Step 4   Start the migration batch
  • Step 5   Configure your MX record to point to Office 365
  • Step 6   Delete the migration batch
  • Best practices
  • Next steps

What happens during a cutover Exchange migration

When you migrate Exchange mailboxes to the cloud in a cutover Exchange migration:

  • The migration service provisions new mailboxes in your cloud-based organization. It creates a cloud-based mailbox for each user account in your on-premises Exchange organization. On-premises distribution groups and contacts are also migrated to the cloud.
  • After the new cloud-based mailboxes are created, the migration service migrates e-mail messages, contacts, and calendar items from the Exchange mailboxes to the corresponding cloud-based mailboxes.
  • After the initial migration, the Exchange and cloud-based mailboxes are synchronized every 24 hours, so that new e-mail sent to the Exchange mailbox is copied to the corresponding cloud-based mailbox. This process is called incremental synchronization.

When you're ready, you can route e-mail directly to the cloud-based mailboxes and delete the migration batch. Then you can remove your on-premises Exchange organization if you want.

Before you begin

Important

If you’ve activated and installed the Microsoft Online Services Directory Synchronization tool, you can’t run a cutover Exchange Migration. If you’ve installed the directory synchronization tool, you can deactivate directory synchronization and then run a cutover Exchange migration. For more information, see Manage directory synchronization.

  • Configure Outlook Anywhere on your on-premises Exchange server   The e-mail migration service uses RPC over HTTP, or Outlook Anywhere, to connect to your on-premises Exchange server. For information about how to set up Outlook Anywhere for Exchange 2010, Exchange 2007, and Exchange 2003, see the following:

    Important   Your Outlook Anywhere configuration must be configured with a certificated trusted by a certificate authority (CA). It can't be configured with a self-signed certificate. For more information, see How to Configure SSL for Outlook Anywhere.

  • Verify that you can connect to your Exchange organization using Outlook Anywhere   Try one of these connection methods:

    • Use Microsoft Office Outlook from outside your corporate network to connect to Exchange.

    • Use the Microsoft Exchange Remote Connectivity Analyzer (ExRCA) to test your connection settings.

    • Run the following Windows PowerShell commands.

      $PSCredentials = Get-Credential

Test-MigrationServerAvailability -Autodiscover -EmailAddress <migration administrator e-mail address> -Credentials $PSCredentials

  • Assign the migration administrator permissions to access mailboxes in your Exchange organization   The on-premises account that you use to run a migration batch must have the necessary permissions to access all user mailboxes. You can assign the Full Access permission for individual mailboxes or assign the Receive As permission for a mailbox database. For more information, see the following:

    Exchange 2010

    Allow Mailbox Access

    Exchange 2007

    Exchange 2003

  • Add your Exchange organization as an accepted domain of your cloud-based e-mail organization   The migration service uses the SMTP address of your on-premises mailboxes to create the Windows Live ID (and e-mail address) for the new cloud-based mailboxes. Migration will fail if your Exchange domain isn't an accepted domain (or the primary domain) of your cloud-based organization. For more information, see Create Accepted Domains - Office 365 for enterprises.

  • Verify that user mailboxes aren’t hidden in on-premises address lists   Migration will fail for on-premises mailboxes that are hidden from address lists. If a user’s mailbox is hidden, clear the Hide from Exchange Address lists checkbox on the user’s properties page in the Exchange Management Console.

  • **Disable unified messaging   **If the mailboxes you are migrating are enabled for unified messaging (UM), you have to disable UM on the mailboxes before you migrate them. You can then enable UM on the mailboxes after the migration is complete. For more information, see Plan to Migrate UM-Enabled Mailboxes.

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Step 1   Create the migration batch

  1. Select Manage My Organization > Users & Groups > E-Mail Migration > New. On the Welcome to E-mail Migration page, select one of the following migration types:
    • Exchange 2007 and later versions - Automatically detect connection settings with Autodiscover   Select this option if you want the migration service to automatically connect to your on-premises Exchange server using the Autodiscover service.
    • Exchange 2003 and later versions - Manually specify connection settings   Select this option if your on-premises messaging system is running Exchange 2003 or if you are running a later version but want to manually provide the connection settings to your on-premises mail server.
  2. Click Next after you select a migration type.

Step 2   Configure the connection settings

Provide the credentials and connection settings for your on-premises Exchange server depending on the migration type that you selected. Perform only one of the following tasks based on your migration type.

Automatically detect connection settings with Autodiscover

  1. If you selected this migration type, configure the migration to use the Autodiscover service to detect the connection settings. The connection settings you configure will persist on this page the next time you start E-Mail Migration to run a new migration batch.

    In this field… Do this…

    * Migration administrator e-mail address

    Type the e-mail address for an administrator account that has access to your Exchange server and all mailboxes.

    * Domain\Username

    Type the username for the migration administrator account. Use the Domain\Username or UPN format.

    * Password

    Type the password for the migration administrator account.

    Number of mailboxes to migrate simultaneously

    Specify the number of connections to the Exchange server available to migrate mailboxes to the cloud. If the value is set to 3, the default value, you can migrate up to three mailboxes at the same time until all the mailboxes in the migration batch have been migrated. The maximum number of connections is 10. To learn more about how to optimize this setting, see Maximum Number of Connections to Your Mail Server.

  2. Click Next. Microsoft Exchange tries to communicate with the on-premises Exchange server to verify the Autodiscover connection settings. If the test connection isn't successful, you’re prompted to manually specify the connection settings. You have to connect to the Exchange server to continue.
    If you can’t connect to your on-premises Exchange server, see this video for troubleshooting tips.
    When the connection to the Exchange server is successful, the migration service connects to the directory on the on-premises Exchange server and queries it to get a list of the mailboxes, distribution groups, and contacts that will be migrated. It might take a while to collect this information.
    When this query process is complete, the Specify what and how to migrate (Step 2 of 3) page is displayed.

Manually specify connection settings

  1. If you selected this migration type, provide the connection settings to your Exchange server.

    In this field… Do this…

    * Domain\Username

    Type the username for the migration administrator account. Use the domain\username format.

    * Password

    Type the password for the migration administrator account.

    * Exchange server

    Type the FQDN of the on-premises Exchange server. For example, EXCH-MSG-1.contoso.com.

    * RPC proxy server

    Type the FQDN of the RPC proxy server for the on-premises Exchange server. For example, mail.contoso.com.

    Authentication

    Select Basic as the authentication method used by the Exchange server.

    Number of mailboxes to migrate simultaneously

    Specify the number of connections to the Exchange server available to migrate e-mail to cloud-based mailboxes. If the value is set to 3, the default value, you can migrate up to three mailboxes at the same time until all the mailboxes in the migration batch have been migrated. The maximum number of connections is 10. To learn more about how to optimize this setting, see Maximum Number of Connections to Your Mail Server.

  2. Click Next. Microsoft Exchange tries to communicate with the on-premises Exchange server to verify the manual connection settings. If the test connection isn't successful, you'll be asked to verify the connection settings. You have to connect to the Exchange server to continue.
    If you can’t connect to your on-premises Exchange server, see this video for troubleshooting tips.
    When the test connection to the Exchange server is successful, the migration service connects to the directory on the on-premises Exchange server and queries it to get a list of the mailboxes, distribution groups, and contacts that will be migrated. It might take a while to collect this information.
    When this query process is complete, the Specify what and how to migrate (Step 2 of 3) page is displayed.

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Step 3   Name the migration batch

In the Batch name field, type a name that identifies the migration batch. This name is displayed in the E-Mail Migration dashboard. Batch names can’t contain spaces or special characters.

To send copies of the migration reports to other users, click Browse to select one or more users.

Click Next to create the migration batch. The Migration batch created successfully (Step 3 of 3) page is displayed. Review the information about the migration batch, and then click Close.

Step 4   Start the migration batch

After you create the migration batch, it’s displayed in the list on the E-mail Migration dashboard. Details about the selected migration batch are displayed in the details pane. The status of the migration batch is set to Created.

To start processing the migration batch, select it and then click Start.

What happens after you start the migration batch?

After you start the migration batch, the status displayed in the details pane in the E-mail Migration dashboard is changed to Queued or Running.

The following table describes the information displayed in the details pane for the migration batch.

Field Description

Status

The current state of the selected migration batch. Includes the following states:

  • Created   Indicates that the migration batch is created. In this state, you can start, edit, or delete the migration batch.
  • Queued   Indicates that the migration batch has been started. In this state, you can stop the migration batch.
  • Running   Indicates that mailboxes in the migration batch are being actively migrated. In this state, you can stop the migration batch.
  • Stopped   Indicates that the migration batch is stopped, and no more mailboxes from the batch are being migrated. In this state, you can re-start the migration batch.
  • Synced   Indicates that migration batch is completed, and no mailboxes are being migrated. A migration batch in this state may contain errors when mailboxes weren’t migrated.

Requested

The number of mailboxes to be migrated in the migration batch.

Synced

The number of mailboxes from the current migration batch that have been created in your cloud-based organization. This field is updated during the migration.

Active

Specifies the number of mailboxes being actively migrated. This number corresponds to the number of mailboxes to migrate simultaneously that you specified when configuring the connection settings.

Errors

The number of mailboxes that failed migration.

Creation Time

Date and time when the migration batch was created.

Start Time

Date and time when the migration batch was started.

Initial Sync Time

Date and time when the migration batch was completed.

Initial Sync Duration

The amount of time it took to complete the migration batch.

Last Synced Time

The last time the migration batch was re-started or the last time that incremental synchronization was performed for the batch.

Per-User Details

Click Open to display status information about each mailbox in the migration batch. For more information, see E-Mail Migration Users Status Report.

Reports

This section of the details pane contains links to the migration statistics and error reports. Links to these reports are sent to the administrator after the migration is complete.

Click Success or Errors to download the following reports:

  • MigrationStatistics   A CSV file that contains a row for each mailbox that was successfully migrated. Each row contains the e-mail address of the mailbox, the status of the migration, the number of mailbox items migrated and the number of mailbox items that were skipped and not migrated.
  • MigrationErrors   A CSV file that contains a row for each mailbox that wasn't migrated or configured for mail forwarding. Each row contains e-mail address of the mailbox and a description of the error.

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Monitor the migration batch

Use the E-mail Migration dashboard and the per-user migration statistics to monitor the status of the migration batch. For more information, see the following:

Stop the migration batch

To stop the migration batch, in the Active E-Mail Migration pane, click Stop.

What happens when you click Stop? The migration of any mailbox currently being processed is stopped immediately and isn't completed. Stopping a migration batch won't affect mailboxes that have been migrated already.

After you stop a migration batch, you receive a status e-mail message that says how many mailboxes were successfully migrated before the batch was stopped. This message also contains a link to the MigrationErrors.csv that identifies the active mailbox migrations that were in progress when the migration was stopped and the rows waiting to be migrated. The status message also contains a link to the MigrationStatistics.csv file that identifies the mailboxes that were successfully migrated.

If you’ve started the migration batch and it has a status of Queued or Running, you can stop it. To stop the migration batch, select it and then click Pause.

When you stop the migration batch that is running, any mailbox currently being processed is stopped immediately and isn't completed. Stopping a migration batch won't affect mailboxes that have been migrated already.

After you stop the migration batch, you receive a status e-mail message that says how many mailboxes were successfully created in the cloud before the batch was stopped, and how many mailboxes weren’t migrated. This message also contains links to the statistics report, which lists the mailboxes that were successfully migrated and to the error report, which lists the mailboxes that weren’t migrated.

Restart the migration batch

If there are errors in the migration batch or if new mailboxes, contacts, or distribution groups were created in your on-premises Exchange organization, you can restart the migration batch. To restart the migration batch, select it and then click Resume.

When you restart the migration batch, the migration service connects to your on-premises Exchange server and queries the directory for new mailboxes, distribution groups, and contacts. When this query is complete, a page displays the number of mailboxes, distribution groups, and contacts that will be migrated.

Note   If you restart the migration batch, the migration service skips the mailboxes, distribution groups, and contacts in your on-premises Exchange organization that have already been migrated.

Step 5   Configure your MX record to point to Office 365

Until you change your MX record, e-mail sent to users is still routed to their on-premises Exchange mailboxes. After a mailbox is successfully migrated, the incremental synchronization process synchronizes the on-premises Exchange mailbox and cloud-based mailbox once every 24 hours until you delete the migration batch. When you configure your organization's MX record to point to your cloud-based e-mail organization, all e-mail is sent directly to the cloud-based mailboxes.

After you change the MX record and verify that all e-mail is being routed to the cloud-based mailboxes, you're ready to delete the migration batch.

Important   It can take from 24 to 72 hours for the updated MX record to be propagated. Wait at least 24 hours after you change the MX record before you delete the migration batch. Verify that mail is being routed to cloud-based mailboxes before you delete the batch.

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Step 6   Delete the migration batch

After all mailboxes in a migration batch have been successfully migrated, verify the following before you delete the migration batch:

  • That mail is being routed to the cloud-based mailboxes after you change your MX record to point to Office 365.
  • That cloud mailboxes were synchronized at least once after mail began being routed directly to cloud mailboxes. To do this, make sure that the value in the Last Synced Time field for the migration batch is more recent than the date and time when mail started being routed directly to cloud mailboxes. This will help ensure that the most recent mail was copied to the cloud mailboxes before mail was routed directly. After you delete the migration batch, on-premises and cloud mailboxes will no longer be synchronized.

To delete a migration batch, select it and then click Delete Delete. When you delete a migration batch, Exchange Online:

  • Cleans up any records related to the migration batch, and then deletes the migration batch.
  • Removes the migration batch from the batch list on the E-mail Migration dashboard.

Best practices

Here are some tips to optimize your Exchange migration:

  • Change the DNS Time-to-Live (TTL) setting on your MX record   Before you start to migrate mailboxes, change the DNS TTL setting on your current MX record to a shorter interval, such as 3600 seconds (one hour). Then, when you change your MX record to point to your cloud-based e-mail organization after all mailboxes are migrated, the updated MX record should propagate more quickly because of the shortened TTL interval.
  • Communicate with your users   Give users a heads-up that you are migrating the content of their on-premises Exchange mailboxes to your cloud-based organization. Consider the following:
    • Ask users to delete old or unnecessary e-mail messages from their Exchange mailbox before migration. This helps reduce the amount of data that has to be migrated and can help reduce the overall migration time. Or you can clean up their mailboxes yourself.
    • Suggest that users to back up their Inbox.
    • Tell users when they can use their cloud-based account to access the e-mail that was migrated from their on-premises account. Don't give users access to their cloud-based accounts until you're ready to complete the migration.
      Need a good way to provide users with their sign-in credentials and autogenerated password for their new cloud-based accounts? See Send a Welcome Message to New Users.

Next steps

  • Assign licenses to Office 365 users   If you have a Microsoft Office 365 e-mail organization, you must assign licenses to new mailboxes or they will be disabled when the grace period ends. For more information, see Assign a License to New Mailboxes in Office 365.

  • Create an Autodiscover DNS record   After all on-premises mailboxes are migrated to the cloud, you can configure an Autodiscover DNS record for your cloud-based organization to enable users to connect to their new cloud-based mailbox with Microsoft Outlook and mobile clients. This new Autodiscover DNS record has to use the same namespace that you’re using for your cloud-based organization. For example, if your cloud-based namespace is cloud.contoso.com, the Autodiscover DNS record you need to create is autodiscover.cloud.contoso.com.
    Exchange Online uses a CNAME record to implement the Autodiscover service for Outlook and mobile clients. The Autodiscover CNAME record must contain the following information:

  • Implement a single sign-on solution   After all mailboxes are migrated to the cloud, you can implement a single sign-on solution to enable users to use their on-premises Active Directory credentials (username and password) to access their Office 365 mailboxes and existing on-premises resources. You implement a single sign-on solution by deploying Active Directory Federation Services 2.0 (AD FS 2.0). For more information, see Cutover Exchange Migration and Single Sign-on.

  • Decommission on-premises Exchange servers   After you verify that all e-mail is being routed directly to the cloud-based mailboxes, have completed the migration, and no longer need to maintain your on-premises e-mail organization or don’t plan on implementing a single sign-on solution, you can uninstall Exchange from your servers and remove your on-premises Exchange organization.

    Important

    If you implement a single sign-on solution, we strongly recommend that you maintain at least one Exchange server so that you can access Exchange System Manager (Exchange 2003) or Exchange Management Console/Exchange Management Shell (Exchange 2007 and Exchange 2010) to manage mail-related attributes on the on-premises mail-enabled users. For Exchange 2007 and Exchange 2010, the Exchange server that you maintain should have the Hub Transport, Client Access, and Mailbox server roles installed.

    For more information, see the following:

    Warning

    Decommissioning Exchange can have unintended consequences. Before decommissioning your on-premises Exchange organization, we recommend that you contact Microsoft Support.

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