Office 365 to Office 365 Mailbox Migration Guide

This guide contains all the necessary steps for migrating users from one Office 365 instance to another with the same domain name.

If this is your first time performing a migration, we have created a Migration Planning & Strategy Guide to walk you through planning, set-up, and general migration best practices. If you have never performed a migration before, we suggest reading that before beginning the steps outlined in this scenario.

MigrationWiz is not a sync tool. Already migrated items updated at the source mid-migration will not be updated at the destination.

MigrationWiz supports the capability to share migration projects across a Workgroup. When the Project Sharing feature is turned on, all active agents can view all migration projects.

We recommend completing this migration with multiple migration passes as instructed in the MigrationWiz steps, as this will cause the least impact on the users.

If either your source or destination have Modern Authentication enabled, there are extra steps that need to be taken in order for MigrationWiz to be able to connect to your environments. Follow the steps in the MigrationWiz - Migration Planning - Modern Authentication for Office 365 article to manage Modern Authentication. 

This guide does not include steps for when using Coexistence during the migration. For the migration strategy guide when using Coexistence, see Office 365 to Office 365 Migration Strategy: While Changing the Domain Name and Using Coexistence.

We are not able to support migrations with two-factor or multifactor authentication. 

 

What Items are Migrated?

Migrated

  • Inbox
  • Folders
  • Email
  • Contacts
  • Calendars
  • Tasks
  • Journals
  • Notes
  • Server-Side Rules
  • Folder Permissions
  • Post (when the destination is Exchange or Office 365)
  • Calendar acceptance status emails

Not Migrated

  • Safe Sender/Block Lists

 

Prepare the Source

Create an Administrator Account

Create an administrator account in Office 365 to be used for migration or use the global admin account for the tenant. The administrator account must have either full access to the user mailboxes or be granted impersonation rights. We recommend using impersonation as it will help reduce the likelihood of the migration being throttled by Microsoft. 

To manually set impersonation:

  • Use admin credentials at the Destination.
  • Sign in to the MigrationWiz account.​
  • Edit the Project and click on Advanced Options.
  • If migrating from Office 365, under Source, check Use impersonation to authenticate.
  • If migrating to Office 365, under Destination, check Use impersonation to authenticate.
  • Click on Save Options.

MigrationWiz will automatically run a remote PowerShell command to allow the admin account to log in to (impersonate) user mailboxes.

 

Export the user list to a CSV file

This can be used when bulk-adding users to your MigrationWiz project later. You can copy and paste the user list into the Source and Destination Email columns within your MigrationWiz project dashboard under Add > Bulk Add.

To export the user list:

  • Go to the Office 365 admin portal
  • Click Users
  • Click Active Users
  • Click Export
  • Click Continue

Be sure to save the csv somewhere you can access it for upload later in the migration.

 

Prepare the Destination

Set Up User Accounts

Set up user accounts on the destination Office 365 tenant and assign licenses. These can be created in several ways. (The following links are to external articles.)

Manually, one at a time.

By bulk import, via CSV file

By PowerShell script

 

Create an Administrator Account

Create an administrator account in Office 365 to be used for migration or use the global admin account for the tenant. The administrator account must have either full access to the user mailboxes or be granted impersonation rights. We recommend using impersonation as it will help reduce the likelihood of the migration being throttled by Microsoft. For specific steps to set impersonation manually, follow the steps in Prepare the Source.

 

Test Administrator Access

Test that the administrator can access user mailboxes.
Test access to the tenantname.onmicrosoft.com addresses, not to the domainname.com addresses. Make sure that the tenantname.onmicrosoft.com account is attached to each mailbox in Office 365. By default, it should be attached, but if not, it will need to be added as an alias to each account. This can be done through the Office 365 admin portal or via PowerShell scripts. 

To test, follow the steps in Prepare the Source.

 

MigrationWiz Steps

Create a Mailbox Migration project

  1. Click the Go to My Projects button.
  2. Click the Create Project button.
  3. Click on the type of project that you wish to create. For this migration:
    • Mailbox: Mailbox projects are used to migrate the contents of the primary user mailbox from the previous environment to the new environment. Most mailbox migrations can migrate email, calendars, and contacts.

For mailbox migrations, use administrative credentials to access mailboxes​. In most migration scenarios, the admin account needs to have full access rights to the Source mailboxes. 

Next:

  1. Click Next Step.
  2. Enter a Project name and select a Customer.
  3. Click Next Step.
  4. Select a Source Endpoint from the Endpoint dropdown menu.
  5. Select a Destination Endpoint from the Endpoint dropdown menu.
  6. Click Save and Go to Summary.

Mailbox Migration Settings: Every setting on the project is applied to all mailboxes associated with that project. For settings that are represented as checkboxes, only selected settings are applied to the project. Not selecting a checkbox does not disable a selected setting inherited from the project.

 

Add Users

Important for users imported from MSPComplete

If the domain name is being migrated to the new destination tenant, it is strongly recommended that users in the migration project be migrated using the OnMicrosoft domain names for both the source and destination email addresses, rather than using the vanity domain.

To do this, you'll add the users using their Vanity Domain and once they're in the project, select all the users and click the Change Domains option in the menu to bulk change them to using the OnMicrosoft domain. 

This process is especially important if you'll be migrating the user's OneDrive data in a document project as the vanity domain is used there.

Add the user accounts that will be migrated to the project. This may be done in several ways, depending on the size of the project. Steps for each option are in the accordion below, simply click to show the option you select and follow the guidance there.

Small Migrations:

For small migrations, it is easy to add users one-at-a-time using Quick Add. The steps for this are below. 

Larger Migrations:

For larger migrations, we recommend either using the Autodiscover or Bulk Add option.

Autodiscover will add all users found on the source tenant. This can then be edited in the project to remove users not being migrated. All users will be added with the source and destination email addresses set to match the source email. This can be changed by using the Change Domain Name button at the top of the project page. If the usernames are changing during the migration, we recommend using the Bulk Add option.

Bulk Add uses a CSV containing the source and destination email addresses for the users to add the users to the project. If migrating only a specific group from a tenant, we recommend using the Bulk Add option.

Quick Add
This option allows you to add items one at a time. You have to enter an email address, login name, and password for each user if you didn't enter administrative credentials when setting up the project. You only have to provide an email address if you entered administrative credentials when setting up the project.
Bulk Add

MigrationWiz allows you to bulk import mailboxes into the system.

To import one or more mailboxes:

  1. Sign in to your MigrationWiz account.
  2. Select the Project for which you want to perform the bulk import.
  3. Click on Add .
  4. Click on Bulk Add .
  5. Follow the instructions on the page.
Autodiscover

​The Autodiscover process within MigrationWiz can be used to discover items from the Source environment, so that they can be imported into your projects.

There are few requirements in order for this to work:

  • The Source has to be Exchange 2007 or later, or Office 365, or G Suite. If you are using Autodiscover from G Suite, all G Suite domains must be added to the list of domains in the Endpoint.
  • The endpoint on the Source needs to use admin credentials.
  • For mailbox migration projects, the admin account that is specified within the Source endpoint needs to have a mailbox associated with it.
  • The admin mailbox must be listed in the public Global Address List (GAL).
  • The migration project type needs to be a Mailbox migration. For the exact steps to be followed during your migration, refer to the relevant Migration Guide. All Migration Guides can be found on the Help Center site.

One additional item to note here is that there is not a way to restrict the IP addresses that the connection will come from.  This means that the steps outlined in our IP Lockdown guide will not apply here.  If your environment requires that any IP addresses be whitelisted, it is recommended that items be added to your project using on of the other available options.

Autodiscover of items will not work while using Modern Authentication

Autodiscovery exposes the following items:

  • For mailbox migration, autodiscovery will list all mailboxes at the Source.

 

Steps to Run Autodiscover

  1. Navigate to the project you want to import users into.

  2. Ensure that you have created an endpoint for the source project.

  3. Once in the project, on the top navigation bar, click on the Add drop-down, then select Autodiscover Items. This will begin the Autodiscover process.

  4. Once discovered, click on the Import button, to import the items into your MigrationWiz project.

 

 

Set the Project Advanced Options

The following options are most valuable for this migration scenario:

Set to use impersonation at the Source. Checkmark the Use impersonation at Source box.

Set to use impersonation at the Destination. Checkmark the Use impersonation at Destination box.

 

Under Support/Support Options:

RecipientMapping="@sourcetenantname.onmicrosoft.com->@destinationdomainname.com" 


The RecipientMapping above is just an example; do not copy this verbatim. It needs to be changed to reflect the sourcetenantname.onmicrosoft.com account name and the customer destination domain name.

This is a very important step for Office 365 to Office 365 migrations. It ensures that emails have the ability to be replied to, even after the Full (Delta) migration has occurred because they will be mapped to the new destination domain name, rather than using the old sourcetenantname.onmicrosoft.com account name (which will no longer be available, once the tenant is retired).

Recipient mappings are a useful way to ensure that:

  • All email remains replyable to, post-migration, even after a Full (Delta) Migration has occurred when performing a tenant to tenant migration, while keeping the same domain name; or when changing domain names from Source to Destination.
  • Calendar ownership and display name match on destination when performing a tenant to tenant migration, while keeping the same domain name; or when changing domain names from Source to Destination.

If you are using recipient mapping while migrating from one Source domain to multiple Destination domains, a project is required for each Destination domain.

If the domain name is changing, then the source vanity domain can be used in the RecipientMapping as in this example: RecipientMapping="@sourcedomainname->@destinationdomainname"

More than one mapping expression can be used as long as the destination domain remains the same in the RecipientMapping.

 

Run Verify Credentials

You may verify the credentials of items in MigrationWiz without migrating data or consuming any licenses.

  1. Open the Project containing items you wish to validate​.
  2. Select the items you wish to validate.
  3. Click on the Start button in your dashboard.
  4. Select Verify Credentials from the drop-down list.

Once complete, the results of the verification will be shown in the Status section.​ 

 

Licensing

Purchase and apply User Migration Bundle licenses for all the users being migrated. For this migration type, we suggest the User Migration Bundle.

  • User Migration Bundle Licenses have unlimited data available per license.
  • User Migration Bundle Licenses are applied to the customer's users and expire 12 months after their purchase date. 
  • Document, Personal Archive, and DeploymentPro projects are all included when using User Migration Bundle Licenses.
  • This license type must be applied manually.

Purchasing Licenses

  1. Sign in to your BitTitan account. 
  2. In the top navigation bar, click Purchase.
  3. Click the Select button and choose the license type you need.
  4. Enter the number of licenses you want to purchase. Click Buy Now.
  5. Enter a Billing address if applicable.
  6. Click Next.
  7. Review the Order Summary and enter a payment method.
  8. Click Place Your Order.

 

Applying User Migration Bundle Licenses

  1. Sign in to MigrationWiz at https://migrationwiz.bittitan.com.
    • You can either sign in and make sure to select the MigrationWiz button above the email field or sign into MSPComplete page, then click the All Products button and select MigrationWiz.
  2. Select the correct workgroup on the top of the left navigation pane.
    Note: This is the workgroup that the customer and migration project were created under. Your account must be part of the workgroup and project sharing must be enabled, if the project was not created under your account. For more information see Add and Edit Workgroups and Project Sharing in MigrationWiz.
  3. Click the project that requires licenses to be applied.
  4. Check the box to the left of the email for the user(s) to whom you want to apply a User Migration Bundle license.
  5. Click the More menu (3 stacked lines) at the top of the project page.
  6. Click Apply User Migration Bundle License.

If you have more questions about licensing, including redeeming coupons, requesting refunds, or changing categories, see MigrationWiz - Licenses.

 

Run a Pre-Stage migration pass

  1. Select the users
  2. Click the Start button from the top
  3. select Pre-Stage Migration
  4. Under the Migration Scheduling section, from the drop-down list, select 90 days ago
  5. Click Start Migration.

The 90 days is a suggestion, you can select any option you prefer. The Pre-Stage migration will migrate only older mail items. This can be run multiple times with different timeframes selected to migrate data in smaller chunks.

 

Remove Domain from Source

This should only be done after the Pre-Stage migration pass has completed. Typically, it is done late on a Friday night. If you need instructions for removing a domain, refer to this document from Microsoft: Remove a domain from Office 365.

If there are several domains in the Source tenant being moved to the new tenant, all of them need to be removed.

In the admin portal, change the UPN of the admin account to the onmicrosoft.com address.

After domain removal, users will not be able to access their email, unless they know and log in with their tenantname.onmicrosoft.com email addresses.

After removal, wait 30 minutes for domain removal replication to complete.

 

Notify Users

Send an email to the users to let them know what to expect for their Outlook profile reconfiguration. If using DeploymentPro, you can use the DeploymentPro Guide now to set up the users on the destination for Outlook profile configuration.

 

Verify Domain at Destination

These actions are performed from within the Tenant 2 (Destination) admin portal.

  1. Verify the domain in the Destination Office 365 account. We recommend the use of the wizard in Office 365 for this since once the domain is verified with the Text record, it offers to change all the users to the new Default Domain. Since the domain was previously added to the account, all that needs to be done is to click the Verify button. If the domain is unable to be verified, and there is an error saying the domain already exists on another account, contact Microsoft Support at 1-866-291-7726 (US Toll-Free, other numbers are also available), and tell them that the domain needs to be manually deprovisioned from Forefront.
  2. Confirm that every user has the Destinationdomain.com domain name added to their mailbox.
  3.  Download the add_new_domain.ps1 PowerShell script to check for this and add the domain name. This is only necessary if the users do not have the new default domain added to their account.

 

MX Record Cutover

On the DNS provider's portal, change the primary MX record to reflect the DNS settings for the new Office 365 organization. DNS settings to change include Autodiscover, MX, and SPF records. Also, remove the old settings for Tenant 1. These settings can be found in the Office 365 admin portal, by following these steps:

  1. Inside Office 365, click Admin in the header.
  2. On the Admin page, click Domains in the left pane.
  3. Click the domain name to be set up, and then click the DNS Settings This page lists the DNS records necessary to set in order to use the Office 365 services.

 

Full (Delta) pass

  1. Select the users
  2. Click the Start button from the top
  3. Select Full Migration
  4. Click Start Migration. This migration will complete quickly since most data is migrated during the Pre-Stage migration; Office 365 to Office 365 migrations have high bandwidth available.
  5. Look through the user list and click any red "failed migration" errors. Review the information and act accordingly.

 

Run Retry Errors

Each error logged represents an item that was not migrated. MigrationWiz contains a mode in which you can resubmit the migration to retry failed items. This mode of operation is always free of charge. You may only submit mailboxes in this mode only if they satisfy all of the following conditions:

  1. The last migration completed successfully.
  2. The mailbox contains at least one error.

If your mailbox does not satisfy these conditions, you will receive a warning when submitting the migration in this mode and your request will not be fulfilled.

To submit one or more mailboxes in retry mode, perform the following steps:

  1. Click the Go To My Projects button.
  2. Select the project that contains the mailboxes that you want to retry.
  3. Select the mailboxes that have migration errors.
  4. Click on the Start button.
  5. Select Retry Errors from the menu.
  6. Click the Retry Errors button.

When errors are repaired, they will disappear from the error log. Some errors may not disappear if the Source item was not reprocessed (due to filters, for example), has been deleted or moved, or if the item failed again. 

If problems persist, contact Support

 

Post-Migration

If not using DeploymentPro, users must create new Outlook profiles, set up their signatures again, and reattach any PST files that were attached to their previous profile.

Click the bar chart icon in the MigrationWiz dashboard to receive an email containing all the project migration statistics. 

Was this article helpful?
3 out of 3 found this helpful