This is the complete onboarding task flow for migrating mailboxes from one Microsoft 365 tenant to another Microsoft 365 tenant.
This migration scenario is useful if you want to migrate data from individual mailboxes into shared Microsoft 365 Groups mailboxes. This migration scenario only supports the migration of mail items into the Microsoft 365 Groups.
First time?
This migration guide contains the necessary steps to perform the actual migration, but there are many steps to preparing for migration. 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.
MigrationWiz
MigrationWiz is a migration tool, not a syncing tool. If changes are made at the source after migration, they will not sync to the destination, nor will changes made at the destination sync to the source. We do not have “live” monitoring of changes (as with a sync agent) and we cannot handle scenarios such as conflict resolution without user interaction.
Prerequisites
It is important to highlight and meet the following prerequisites for a smooth migration project.
- Exchange Web Services (EWS) must be enabled for the mailboxes in the Exchange Online tenant.
Licensing
We recommend that you purchase User Migration Bundle licenses for this migration scenario. User Migration Bundle licenses allow the performance of multiple migrations with a single license. For questions on licensing, visit MigrationWiz Licenses.
To use your license by following the next steps:
- Purchase Licenses.
- Create a Customer.
- Apply Licenses.
- Review Considerations.
Purchase licenses by following the steps below:
- Sign in to your BitTitan account.
- In the top navigation bar, click Purchase.
- Click the Select button and choose User Migration Bundle licenses.
- Enter the number of licenses you want to purchase. Click Buy Now.
- Enter a Billing address if applicable.
- Click Next.
- Review the Order Summary and enter a payment method.
- Click Place Your Order.
Create Customer on MSPComplete by performing these steps:
- Click the Add button in the top navigation bar
- Click the Add Customer button on the All Customers page
- Select the appropriate workgroup in the left navigation pane and click All Customers.
- Click Add Customer.
- Enter the new customer’s information in the Add Customer form. Primary Email Domain and Company Name are required. The rest are optional.
- Click Save.
- Repeat steps 1 through 4 for each customer you want to add.
Perform these steps on MSPComplete:
- Select the correct workgroup on the top of the left navigation pane.
Important
This is the workgroup which the customer and migration projects were created under. Your account must be part of the workgroup if the project was not created under your account. - Click Customers on the left navigation pane.
- Click the customer that employs the user to whom you want to use the User Migration Bundle license.
- Click the Users tab at the top of the page.
- Apply the license to the users by checking the box to the left of their emails.
- Click the Apply User Migration Bundle License button at the top of the page.
Tip
We recommend adding users to the Customer page with the vanity domain. Then apply the User Migration Bundle Licenses, before editing to show the .onmicrosoft domain, if the .onmicrosoft domain will be used for the migration. - Click Confirm if at least one unassigned User Migration Bundle license is available for each selected user.
Important
If there are no User Migration Bundle licenses currently available to be assigned and your role in the workgroup is Manager or higher, the form that appears provides all the necessary information and will walk you through the steps of purchasing User Migration Bundle licenses.
Licenses are released once payment has been received:
- Licenses are available immediately upon payment if you purchase via credit card.
- If you purchase via wire transfer (100+ licenses), the licenses will be available once payment is received and accepted.
- We do not accept purchase orders because of processing overhead.
In both cases, you will be notified by email that payment has been accepted and licenses are available in your account upon notification.
For more information on licensing, including coupon redemption and other licensing types, see our Licensing FAQ.
Limitations
- We are not able to support migrations with two-factor or multifactor authentication.
- App password usage, MFA/2FA, and ADFS are not supported for the migration service account being used by this endpoint.
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The maximum file size for migration through MigrationWiz varies by migration type and environment, but may never exceed 60GB.
Warning
MigrationWiz no longer supports Teams private chat history as part of Mailbox migrations due to Microsoft's restriction on Teams data access through EWS. For more information please review this article.
Migrated Items
Please click the bars below to check the migrated and non-migrated items. We are constantly working to create a better migration experience for you so these items may change over time.
- Inbox
- Folders
- Contacts
- Calendars
- Tasks
- Journals
- Notes
- Server-Side Rules
- Folder Permissions
- Post (when the destination is Exchange or Microsoft 365)
Non-Migrated
- Safe Sender/Block Lists
- In-line images in Tasks
- Private Chats
- Calendar acceptance status emails
Groups Documents
- Notebooks
- Anything not in a document library (See SharePoint)
Prepare the Source Environment
EWS (Exchange Web Services) Access in Exchange Online
Microsoft has announced significant updates to how Exchange Web Services (EWS) access will be managed in Exchange Online, effective April 2025.
After this change EWS access will only be allowed if both the organization-level and user-level EWSEnabled settings are set to True. If either setting is set to False, EWS access will be blocked. For further information regarding this topic, please review the following Microsoft article. If you need assistance on this topic, please contact BitTitan's support team.
Retirement of Exchange Web Services in Exchange Online
Microsoft has officially announced that Exchange Web Services (EWS) requests will be blocked in Exchange Online beginning October 1, 2026. Read Microsoft’s announcement.
At this time, no action is required from MigrationWiz users. We are taking the necessary steps to transition to Microsoft Graph API and ensure continued service without disruption.
Modern Authentication Requirements
The steps listed in the Required Permission for Performing M365 Mailbox and Archive Migrations article apply to both the source and destination tenant when they are Exchange Online, in regards to Exchange Web Services (EWS) in the mailbox and archive mailbox. Use a Global Administrator for the configuration steps.
Please review the documentation before preparing the source.
Create a Migration Service Account
Create a migration service account in Microsoft 365 for the tenant, this account does not require any admin role assigned. However, it must have full access to the user mailboxes or have the required API Permissions.
We recommend adding the necessary API permissions to the Modern Authentication app you are using for your O365 mailbox or archive mailbox endpoint. You can follow the steps outlined in this guide, as this is BitTitan's recommended approach.
Deprecation of Microsoft Application Impersonation Role
From February 2025, Microsoft has started the depreciation process to remove the Application Impersonation role from O365. Exchange On-premise and Hosted Exchange are not affected by these changes. For further information please see this article.
If you are currently using Application Impersonation for your migrations, there is no telling when that will eventually fail. It is highly recommended that you switch to using the new API permission process to avoid delays in your project due to permission failures.
Prepare the Destination Environment
EWS (Exchange Web Services) Access in Exchange Online
Microsoft has announced significant updates to how Exchange Web Services (EWS) access will be managed in Exchange Online, effective April 2025.
After this change EWS access will only be allowed if both the organization-level and user-level EWSEnabled settings are set to True. If either setting is set to False, EWS access will be blocked. For further information regarding this topic, please review the following Microsoft article. If you need assistance on this topic, please contact BitTitan's support team.
Retirement of Exchange Web Services in Exchange Online
Microsoft has officially announced that Exchange Web Services (EWS) requests will be blocked in Exchange Online beginning October 1, 2026. Read Microsoft’s announcement.
At this time, no action is required from MigrationWiz users. We are taking the necessary steps to transition to Microsoft Graph API and ensure continued service without disruption.
Modern Authentication Requirements
The steps listed in Authentication Methods for Microsoft 365 (All Products) Migrations apply to both the source and destination tenant when they are Exchange Online, in regards to Exchange Web Services (EWS) in mailbox, archive mailbox, and public folder projects. Use a Global Administrator for the configuration steps.
Please review the documentation before preparing the destination.
Create a Migration Service Account
Create a migration service account in Microsoft 365 for the tenant, this account does not require any admin role assigned. However, it must have full access to the user mailboxes or have the required API Permissions.
We recommend adding the necessary API permissions to the Modern Authentication app you are using for your O365 mailbox or archive mailbox endpoint. You can follow the steps outlined in this guide, as this is BitTitan's recommended approach.
Deprecation of Microsoft Application Impersonation Role
From February 2025, Microsoft has started the depreciation process to remove the Application Impersonation role from O365. Exchange On-premise and Hosted Exchange are not affected by these changes. For further information please see this article.
If you are currently using Application Impersonation for your migrations, there is no telling when that will eventually fail. It is highly recommended that you switch to using the new API permission process to avoid delays in your project due to permission failures.
Create the Microsoft 365 Groups
This step is only necessary if the group does not already exist. Either of these options can create Microsoft 365 Groups:
- Opening Outlook Web Access / Outlook On The Web.
- Via PowerShell, using the New-UnifiedGroup command.
- Created in the Microsoft 365 admin portal.
Manage Group Membership
The following actions may be performed to manage group membership before migration.
- Add members to the Group using the Microsoft 365 admin center.
- Add the migration service account as a member of the group.
- Add the migration service account as an owner of the group.
MigrationWiz Steps
Create the Mailbox Migration Project
You will now create the migration project and add your users.
Once a project is set up, you cannot add more users or make changes to the configuration except for advanced options. If you want to add users to the organization, please add them to the source before creating the project or add them manually to the destination. Once the project is created, users will be added to the project automatically from the source endpoint.
- Click the Go To My Projects button.
- Click the Create Project button.
- Create a Mailbox migration.
- Click Next Step.
Endpoints
Endpoints are created through MigrationWiz. If you select an existing endpoint from the dropdown, it will only show ten endpoints. If you have more than ten, you may need to search it.
Consider that endpoint search is case and character-specific. For example, Cust0mer will not show up if the search is customer. We recommend keeping a list of endpoints you have created, along with any unique spellings or capitalization you may have used.
Create your Endpoints
Please review the following tabs to create your destination and source endpoints.
Create your source endpoint by following the next steps:
- Click Endpoints.
- Click Add Endpoint.
- Enter the endpoint name.
- Select endpoint type Microsoft 365.
- Enter the administrator username and password in the proper fields. This should be the migration service account in the Prepare the Source section.
- Complete the Application (client) ID, the Directory (tenant) ID, and the Client Secret fields.
- Click Next Step.
Create your destination endpoint by following the next steps:
- Click New.
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Enter a name in the Endpoint Name field.
- Select the Microsoft 365 service provider.
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Choose Microsoft 365 Groups from the Endpoint Type drop-down menu.
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Enter the SharePoint top-level domain URL. Although the SharePoint URL would not be used in the Exchange Online to Microsoft 365 Groups migration, we recommend it as a good practice and for future development.
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Enter the administrator credentials, Administrator username, and password.
- Click Add to save your destination endpoint.
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Complete the Application (client) ID, the Directory (tenant) ID, and the Secret Client fields, otherwise, you cannot save your project.
- Click Next Step.
Application (client) ID, Directory (tenant) ID, and Client Secret
For Microsoft 365 Mailbox and Archive migrations, MigrationWiz adds the Application (client) ID, Directory (tenant) ID, and Client Secret fields.
While the Application (client) ID and the Directory (tenant) ID are mandatory, the Client Secret field is not. It will depend on the permissions of the user account that performs the migration. Please review the following information before the creation of your M365 endpoints.
- Do not use the client secret value if you use delegated permissions (not the most recommended approach). When using delegated permissions, do not select the Use Impersonation to Authenticate checkbox in the source/destination tab of your project's advanced options.
- The client secret value is mandatory if you using the API Permissions approach.
- If you already have a migration service account with the Impersonation role enabled (not using the API Permissions approach) the client secret value is not mandatory. Please leave the Client Secret field empty.
Warning
Keep in mind that Microsoft has started removing the application impersonation role from O365, meaning there is no telling when that will eventually fail. It is highly recommended that you switch to the API Permissions approach.
For more information about how to get the Application (client) ID and Directory (tenant) ID values from the Application Registration, please review step 3 of this article.
Region of Destination Tenant
The Region of Destination Tenant feature optimizes migration performance and speed by identifying the region closest to the destination tenant (continent-level). For Microsoft 365 endpoints, MigrationWiz detects and selects the appropriate region automatically once you create and save your project.
Please note that each time you edit your project endpoints, the following message will appear at the top of your project window (where XXXX is the detected region):
Automatically detected destination tenant's region and assigned to the 'BitTitan Datacenter' in XXXX.
For this migration type, you cannot manually change the region of the destination tenant. In case you need to modify it, contact our support team.
Project Settings
Once the endpoint configuration is complete, the Project Settings window will open. In this window, you can choose from the following options based on your requirements:
- Skip Modern Auth Credential Validation: By choosing this option you will disable the Modern Auth verification across all endpoints.
Endpoint Validation
Once the information has been provided for both, the source and destination endpoint, and the customer selects Save and Go to Summary, MigrationWiz performs an endpoint validation check.
This validation tests the migration service account credentials entered into the project and the Modern Authentication setup only. If there is an issue, the screen redirects to the endpoint and provides an error message or flyout that can be selected for more information regarding the error.
Common Errors when Configuring Your Endpoint
For more information, review the AADSTS700016, AADSTS90002, and ADDSTS50126 issues on the Common Errors Using Modern Authentication page.
Add User Accounts
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.
- An email address
- Login name
- Password
- Mailbox status
MigrationWiz allows you to bulk import mailboxes into the system.
To import one or more mailboxes:
- Sign in to your MigrationWiz account.
- Select the Project for which you want to perform the bulk import.
- Click Add.
- Click Bulk Add.
- Follow the instructions on the page.
Export the User List to a CSV File
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 Microsoft 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.
Autodiscover process within MigrationWiz can be used to discover items from the Source environment so that they can be imported into your projects. This can then be edited in the project to remove users not being migrated. All users are 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.
There are a few requirements for this to work:
- The Source has to be Exchange 2007 or later, or Microsoft 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 no 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 one 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
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Navigate to the project you want to import users into.
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Ensure that you have created an endpoint for the source project.
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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.
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Once discovered, click on the Import button, to import the items into your MigrationWiz project.
Advanced Options
The following option is the most valuable for this migration scenario.
Support Tab
Default Options for Microsoft 365 Endpoints
By default, some fields are view-only. In other words, you cannot edit or remove them from the support options page. To edit them, you need to edit the source or destination endpoint of your project.
Among these default options, you can find ModernAuthClientIdExport, ModernAuthTenantIdExport, ModernAuthClientSecretExport, ModernAuthClientIdImport, ModernAuthTenantIdImport, and ModernAuthClientSecretImport.
The support options above are required when configuring your endpoint.
Important
Keep in mind that the ModernAuthClientSecretExport and the ModernAuthClientSecretImport support options are text-masked.
Warning
You cannot update the default Advanced Options, in case you try to modify or add new ones the following message arises.
Source/Destination Tab
For now, the new API Permissions approach does require the Use Impersonation to Authenticate box checked for your O365 endpoints along with the Client secret value that you supplied during the Endpoint creation.
Filtering Tab
- ^(?!Inbox$). This RegEx expression migrates the Inbox, but not its subfolders. To migrate both the Inbox folder and Calendars folder, use instead the RegEx expression ^(?!Inbox$|Calendar$). These filters are used to prevent failures, as Groups should only contain an Inbox folder, and possibly a Calendar. No other folders are supported. This expression must be in the source language, such as ^(?!Boîte de réception$) for French.
Run Verify Credentials
You may verify the credentials of items in MigrationWiz without migrating data or consuming any licenses.
- Open the Project containing items you wish to validate.
- Select the items you wish to validate.
- Click the Start button in your dashboard.
- Select Verify Credentials from the drop-down list.
Once complete, the results of the verification will be shown in the Status section.
Notify Users
Notify users that a migration is occurring. Send an email to all users telling them the time and date of the migration.
MX Record Cutover
Change over MX records on the DNS providers' portal. Also, include the AutoDiscover (CName) setting.
Send an email to end users to let them know what to expect for their Outlook profile reconfiguration.
Run Migration
You are now ready to run the migration.
- Select the users.
- Click the Start button from the top.
- Select Full Migration.
- Select to migrate Mail only.
- Click Start Migration.
Run Retry Errors
Look through the user list and click any red "failed migration" errors. Review the information and act accordingly. 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:
- The last migration pass was completed successfully.
- 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:
- Sign into your MigrationWiz account.
- Click the Go To My Projects button.
- Select the project that contains the mailboxes that you want to retry.
- Select the mailboxes that have migration errors.
- Click on the Start button.
- Select Retry Errors from the menu.
- 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
- Show users how to access the Microsoft 365 Group; this will appear in their Outlook, under Groups.
- Click the pie chart icon in the MigrationWiz dashboard to receive an email containing all the project migration statistics.