Migrate e-mail to Exchange Online using the Exchange cutover method

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As part of a Microsoft 365 or Role 365 deployment, you can migrate the contents of user mailboxes from a source email system to Microsoft 365 or Office 365. When y'all do this all at one fourth dimension, it'southward chosen a cutover migration. Choosing a cutover migration is suggested when:

  • Your electric current on-bounds Substitution organization is Microsoft Substitution Server 2003 or later.

  • Your on-bounds Commutation organisation has fewer than two,000 mailboxes.

    Note

    Even though cutover migration supports moving upwardly to 2000 mailboxes, due to length of time information technology takes to create and migrate 2000 users, it is more reasonable to migrate 150 users or fewer.

Plan for migration

Setting up an email cutover migration to Microsoft 365 or Part 365 requires careful planning. Before yous begin, here are a few things to consider:

  • Y'all can motion your entire email organization to Microsoft 365 or Office 365 over a few days and manage user accounts in Microsoft 365 or Office 365.

  • A maximum of 2,000 mailboxes tin can be migrated to Microsoft 365 or Office 365 by using a cutover Exchange migration. However, it is recommended that yous only migrate 150 mailboxes.

  • The primary domain name used for your on-premises Exchange organization must be an accepted every bit a domain owned by you in your Microsoft 365 or Office 365 organization.

  • After the migration is complete, each user who has an on-premises Exchange mailbox also will exist a new user in Microsoft 365 or Office 365, simply you must even so assign licenses to users whose mailboxes are migrated.

    Annotation

    When migrating from Exchange 2003, TCP port 6001, 6002 and 6004 need to be open on the Commutation 2003 side.

Impact to users

After your on-premises and Microsoft 365 or Office 365 organizations are set for a cutover migration, mail-setup tasks could impact your users.

  • Administrators or users must configure desktop computers: Make sure that desktop computers are updated and set up for use with Microsoft 365 or Role 365. These actions allow users to use local user credentials to sign in to Microsoft 365 or Role 365 from desktop applications. Users with permission to install applications can update and set their own desktops. Or updates tin can be installed for them. Later updates are made, users can send email from Outlook 2013, Outlook 2010, or Outlook 2007.

  • Potential delay in email routing: Email sent to on-premises users whose mailboxes were migrated to Microsoft 365 or Role 365 are routed to their on-premises Commutation mailboxes until the MX tape is changed.

How does cutover migration piece of work?

The master steps you perform for a cutover migration are shown in the following illustration.

Process for performing a cutover email migration to Microsoft 365 or Office 365.

  1. The administrator communicates upcoming changes to users and verifies domain buying with the domain registrar.

  2. The administrator prepares the servers for a cutover migration and creates empty postal service-enabled security groups in Microsoft 365 or Part 365.

  3. The ambassador connects Microsoft 365 or Office 365 to the on-premises email system (this is called creating a migration endpoint).

  4. The administrator migrates the mailboxes and then verifies the migration.

  5. Grant Microsoft 365 or Office 365 licenses to your users.

  6. The administrator configures the domain to begin routing email directly to Microsoft 365 or Office 365.

  7. The administrator verifies that routing has changed, and then deletes the cutover migration batch.

  8. The administrator completes postal service-migration tasks in Microsoft 365 or Office 365 (assigns licenses to users and creates an Autodiscover Domain Name System (DNS) tape), and optionally decommissions the on-premises Exchange servers.

  9. The ambassador sends a welcome letter to users to tell them well-nigh Microsoft 365 or Part 365 and to describe how to sign in to their new mailboxes. (Run across Overview of Outlook e-mail profile for information on creating new Outlook profiles).

Prepare to run a cutover migration?

Aggrandize the sections below and follow the steps.

Gear up for a cutover migration

Before you migrate mailboxes to Microsoft 365 or Office 365 by using a cutover migration, in that location are a few changes to your Exchange Server surround yous must consummate first.

Note

If you lot have turned on directory synchronization, yous need to turn it off before you can perform a cutover migration. You tin do this by using PowerShell. For instructions, see Turn off directory synchronization.

  1. Configure Outlook Anywhere on your on-premises Commutation Server: The email migration service uses Outlook Anywhere (also known as RPC over HTTP), to connect to your on-premises Exchange Server. Outlook Anywhere is automatically configured for Exchange 2013. For information about how to prepare Outlook Anywhere for Exchange 2010, Exchange 2007, and Exchange 2003, see the following:

    • Exchange 2010: Enable Outlook Anywhere

    • Exchange 2007: How to Enable Outlook Anywhere

    • How to configure Outlook Anywhere with Exchange 2003

  2. Y'all must apply a certificate issued by a trusted certification authorization (CA) with your Outlook Anywhere configuration in club for Microsoft 365 or Office 365 to run a cutover migration. For cutover migration y'all will to add the Outlook Anywhere and Autodiscover services to your certificate. For instructions on how to set certificates, run across:

    • Add an SSL document to Commutation 2013

    • Add an SSL certificate to Exchange 2010

    • Add an SSL certificate to Exchange 2007

  3. Optional: Verify that you can connect to your Exchange organization using Outlook Anywhere: Try one of the following methods to test your connection settings.

    • Use Outlook from exterior your corporate network to connect to your on-premises Exchange mailbox.

    • Use the Microsoft Exchange Remote Connectivity Analyzer to test your connexion settings. Utilize the Outlook Anywhere (RPC over HTTP) or Outlook Autodiscover tests.

    • Look for the connectedness to automatically be tested when you connect Microsoft 365 or Office 365 to your e-mail organisation later in this procedure.

  4. Ready permissions: The on-premises user account that you employ to connect to your on-premises Commutation organization (also chosen the migration administrator) must have the necessary permissions to access the on-premises mailboxes that you want to drift to Microsoft 365 or Office 365. This user account is used when you connect Microsoft 365 or Office 365 to your e-mail system later in this procedure. To migrate the mailboxes, the admin must have ane of the following permissions:

    • The migration administrator must be assigned the FullAccess permission for each on-bounds mailbox.

    or

    • The migration administrator must exist assigned the Receive As permission on the on-bounds mailbox database that stores user mailboxes.

    For instructions near how to set these permissions, see Assign Exchange permissions to drift mailboxes to Microsoft 365 or Function 365.

  5. Verify that the mailboxes to exist migrated are not hidden from the address lists.

  6. Disable Unified Messaging (UM): If UM is turned on for the on-premises mailboxes you lot're migrating, turn off UM before migration. Plow on Deject Voicemail for your users after the migration is complete.

  7. Create security groups and make clean up delegates: Considering the email migration service can't detect whether on-premises Active Directory groups are security groups, it can't provision whatever migrated groups as security groups in Microsoft 365 or Office 365. If you want to have security groups in Microsoft 365 or Office 365, you must offset provision an empty mail-enabled security group in Microsoft 365 or Office 365 before starting the cutover migration.

    Additionally, this migration method just moves mailboxes, mail users, post contacts, and mail-enabled groups with their membership. If any other Active Directory object, such as user mailbox that is not migrated to Microsoft 365 or Office 365 is assigned equally a director or delegate to an object beingness migrated, y'all must remove them from the object before migration.

Step 1: Verify you own the domain

During the migration, the Simple Mail Transfer Protocol (SMTP) address of each on-premises mailbox is used to create the electronic mail accost for a new Microsoft 365 or Office 365 mailbox. To run a cutover migration, the on-premises domain must be a verified domain in your Microsoft 365 or Office 365 organization.

  1. Sign in to Microsoft 365 or Office 365 with your work or school business relationship.

  2. Choose Setup > Domains.

  3. On the Domains- page, click Add domain to start the domain wizard.

    Choose Add domain.

  4. On the Add a domain page, type in the domain proper noun (for example, Contoso.com) you use for your on-premises Substitution organization, and then choose Next.

  5. On the Verify domain page, select either Sign in to GoDaddy (if your DNS records are managed by GoDaddy) or Add a TXT tape instead for any other registrars > Adjacent.

  6. Follow the instructions provided for your DNS hosting provider. The TXT record usually is chosen to verify ownership.

    You can also detect the instructions in Add together DNS records to connect your domain.

    Later you add together your TXT or MX record, wait about 15 minutes before proceeding to the next step.

  7. In the Office 365 domain sorcerer, cull done, verify now, and you'll see a verification page. Choose Finish.

    If the verification fails at offset, look awhile, and try again.

    Do not go along to the next step in the domain wizard. Y'all now have verified that you lot own the on-bounds Commutation organization domain and are ready to continue with an email migration.

Footstep 2: Connect Microsoft 365 or Function 365 to your email system

A migration endpoint contains the settings and credentials needed to connect the on-bounds server that hosts the mailboxes yous're migrating with Microsoft 365 or Office 365. The migration endpoint also defines the number of mailboxes to migrate simultaneously. For a cutover migration, you'll create an Outlook Anywhere migration endpoint.

  1. Go to the Exchange admin center.

  2. In the Exchange admin middle, become to Recipients > Migration.

  3. Choose More than More icon. > Migration endpoints.

    Select Migration endpoint.

  4. On the Migration endpoints page, choose New New icon..

  5. On the Select the migration endpoint type page, cull Outlook Anywhere > Next.

  6. On the Enter on-premises account credentials page, enter information in the post-obit boxes:

    • Email accost: Type the email address of any user in the on-premises Exchange organization that will be migrated. Microsoft 365 or Role 365 will test the connectivity to this user's mailbox. Make sure that this mailbox is not hidden from the address lists.

    • Account with privileges: Blazon the username (domain\username format or an electronic mail accost) for an account that has the necessary administrative permissions in the on-premises organization. Microsoft 365 or Office 365 will apply this business relationship to detect the migration endpoint and to exam the permissions assigned to this account by attempting to access the mailbox with the specified email accost.

    • Password of account with privileges: Type the password for the account with privileges that is the ambassador account.

  7. Choose Next and do 1 of the following:

    • If Microsoft 365 or Role 365 successfully connects to the source server, the connection settings are displayed. Choose Next.

      Confirmed connection for Outlook Anywhere endpoint.

    • If the exam connection to the source server isn't successful, provide the following data:

    • Exchange server: Type the fully qualified domain name (FQDN) for the on-premises Exchange Server. This is the host name for your Mailbox server. For example, EXCH-SRV-01.corp.contoso.com.

    • RPC proxy server: Blazon the FQDN for the RPC proxy server for Outlook Anywhere. Typically, the proxy server is the same every bit your Outlook on the web (formerly known as Outlook Spider web App) URL. For instance, post.contoso.com, which is also the URL for the proxy server that Outlook uses to connect to an Exchange Server

  8. On the Enter general data page, type a Migration endpoint proper name, for example, Test5-endpoint. Leave the other ii boxes blank to apply the default values.

    Migration endpoint name.

  9. Choose New to create the migration endpoint.

    To validate your Exchange Online is connected to the on-premises server, you can run the command in Example iv of Examination-MigrationServerAvailability.

Step 3: Create the cutover migration batch

In a cutover migration, on-bounds mailboxes are migrated to Microsoft 365 or Office 365 in a single migration batch.

  1. In the Exchange admin center, go to Recipients > Migration.

  2. Choose New New icon. > Migrate to Commutation Online.

    Select Migrate to Exchange Online.

  3. On the Select a migration blazon page, choose Cutover migration > side by side.

  4. On the Ostend the migration endpoint page, the migration endpoint data is listed. Verify the information and so choose adjacent.

    New migration batch with confirmed endpoint.

  5. On the Motion configuration page, blazon the proper name (cannot contain spaces or special characters) of the migration batch, and then cull next. The batch name is displayed in the list of migration batches on the Migration folio later on y'all create the migration batch.

  6. On the Start the batch page, cull one of the post-obit:

    • Automatically first the batch: The migration batch is started as soon every bit y'all salve the new migration batch with a condition of Syncing.

    • Manually commencement the batch after: The migration batch is created merely is not started. The status of the batch is set to Created. To start a migration batch, select it on the migration dashboard, and then cull Start.

  7. Choose new to create the migration batch.

    The new migration batch is displayed on the migration dashboard.

Step 4: Start the cutover migration batch

If yous created a migration batch and configured it to be started manually, you can start it past using the Exchange admin center.

  1. In the Exchange admin eye, go to Recipients > Migration.

  2. On the migration dashboard, select the batch and and then choose First.

  3. If a migration batch starts successfully, its condition on the migration dashboard changes to Syncing.

    Migration batch is syncing.

Verify the synchronization worked

Y'all'll be able to follow the sync status on the migration dashboard. If there are errors, yous tin view a log file that gives you more than information most them.

Y'all can likewise verify that the users get created in the Microsoft 365 admin heart as the migration proceeds.

After the migration is done, the sync status is Synced.

Optional: Reduce email delays

Although this chore is optional, doing it tin can assist avoid delays in the receiving email in the new Microsoft 365 or Role 365 mailboxes.

When people outside of your arrangement send y'all email, their electronic mail systems don't double-check where to send that email every time. Instead, their systems salve the location of your email system based on a setting in your DNS server known as a time-to-live (TTL). If you modify the location of your email organization before the TTL expires, the sender's email arrangement tries to send e-mail to the old location earlier figuring out that the location changed. This location change can issue in a mail service delivery delay. One style to avoid this is to lower the TTL that your DNS server gives to servers outside of your organization. This will make the other organizations refresh the location of your electronic mail system more than often.

Almost email systems ask for an update each hour if a short interval such equally three,600 seconds (one 60 minutes) is set. We recommend that y'all prepare the interval at least this low before you start the electronic mail migration. This setting allows all the systems that send y'all e-mail enough time to procedure the change. And so, when you brand the final switch over to Microsoft 365 or Function 365, yous can change the TTL back to a longer interval.

The place to alter the TTL setting is on your e-mail system's MX tape. This lives on your public-facing DNS system. If you have more than than 1 MX record, you lot demand to change the value on each record to 3,600 seconds or less.

If you demand some help configuring your DNS settings, see Add together DNS records to connect your domain.

Pace five: Route your email directly to Microsoft 365 or Office 365

Email systems use a DNS record called an MX tape to effigy out where to deliver emails. During the e-mail migration process, your MX record was pointing to your source email system. At present that the electronic mail migration to Microsoft 365 or Office 365 is complete, it'due south fourth dimension to point your MX tape at Microsoft 365 or Office 365. This helps make sure that email is delivered to your Microsoft 365 or Office 365 mailboxes. Moving the MX record will as well let you turn off your former email system when you're ready.

For many DNS providers, there are specific instructions to change your MX tape. If your DNS provider isn't included, or if yous desire to get a sense of the general directions, general MX tape instructions are provided besides.

It tin have upwardly to 72 hours for the e-mail systems of your customers and partners to recognize the inverse MX tape. Wait at least 72 hours earlier you lot keep to the side by side chore: Delete the cutover migration batch.

Step half-dozen: Delete the cutover migration batch

After you change the MX record and verify that all email is being routed to Microsoft 365 or Part 365 mailboxes, notify the users that their post is going to Microsoft 365 or Office 365. Subsequently this y'all can delete the cutover migration batch. Verify the following before yous delete the migration batch.

  • All users are using Microsoft 365 or Role 365 mailboxes. Afterwards the batch is deleted, mail sent to mailboxes on the on-premises Exchange Server isn't copied to the corresponding Microsoft 365 or Part 365 mailboxes.

  • Microsoft 365 or Part 365 mailboxes were synchronized at least once after mail service began being sent directly to them. To do this, brand sure that the value in the Last Synced Fourth dimension box for the migration batch is more than recent than when mail started being routed directly to Microsoft 365 or Function 365 mailboxes.

When you lot delete a cutover migration batch, the migration service cleans upwardly whatever records related to the migration batch so deletes the migration batch. The batch is removed from the list of migration batches on the migration dashboard.

  1. In the Exchange admin middle, get to Recipients > Migration.

  2. On the migration dashboard, select the batch, so cull Delete.

    Note

    It can take a few minutes or the batch to be removed.

  3. In the Exchange admin heart, go to Recipients > Migration.

  4. Verify that the migration batch is no longer listed on the migration dashboard.

Step 7: Assign licenses to Microsoft 365 and Role 365 users

Activate user accounts for the migrated accounts by assigning licenses: If you don't assign a license, the mailbox is disabled when the grace period ends (30 days). To assign a license in the Microsoft 365 admin eye, come across Add users individually or in bulk.

Consummate mail migration tasks

Subsequently migrating mailboxes to Microsoft 365 or Function 365, at that place are post-migration tasks that must be completed.

  1. Create an Autodiscover DNS record so users tin easily go to their mailboxes: Later all on-premises mailboxes are migrated to Microsoft 365 or Office 365, y'all can configure an Autodiscover DNS tape for your Microsoft 365 or Office 365 organization to enable users to hands connect to their new Microsoft 365 or Role 365 mailboxes with Outlook and mobile clients. This new Autodiscover DNS tape has to use the same namespace that you're using for your Microsoft 365 or Role 365 organization. For instance, if your deject-based namespace is cloud.contoso.com, the Autodiscover DNS record you need to create is autodiscover.deject.contoso.com.

    If you lot go along your Exchange Server, you should likewise brand certain that Autodiscover DNS CNAME tape has to bespeak to Microsoft 365 or Part 365 in both internal and external DNS after the migration so that the Outlook customer volition to connect to the correct mailbox. Supercede <ServerName> with the name of the Client Access server and run the post-obit control in the Exchange Management Shell to foreclose client connections to the server. You'll need to run the command on every Customer Admission server.

                      Set-ClientAccessServer -Identity <ServerName> -AutoDiscoverServiceInternalUri $zilch

    Microsoft 365 or Office 365 uses a CNAME record to implement the Autodiscover service for Outlook and mobile clients. The Autodiscover CNAME record must incorporate the following data:

    • Alias: autodiscover

    • Target: autodiscover.outlook.com

    For more than information, see Add DNS records to connect your domain.

  2. Decommission on-bounds Exchange Servers: Subsequently you've verified that all electronic mail is being routed direct to the Microsoft 365 or Part 365 mailboxes, and no longer need to maintain your on-premises email organization or don't program on implementing a single sign-on solution, you can uninstall Commutation from your servers and remove your on-premises Exchange organization.

    For more information, see the post-obit topics:

    • Modify or Remove Exchange 2010

    • How to Remove an Substitution 2007 Arrangement

    • How to Uninstall Exchange Server 2003

    Note

    Decommissioning Exchange tin take unintended consequences. Before decommissioning your on-premises Commutation arrangement, nosotros recommend that you contact Microsoft Support.

See too

Ways to migrate email to Microsoft 365 or Function 365

Decide on a migration path