This is the complete onboarding task flow for migrating mailboxes from IMAP systems to Microsoft 365. 

This guide includes a folder mapping under the MigrationWiz Steps section, which will ensure that folders are mapped to the root label on the Destination mailboxes, rather than under the inbox/label name.

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.

MigrationWiz supports the capability to share migration projects across a Workgroup. When the Project Sharing feature is turned on, all Agents besides those who are Inactive can view all migrations projects.

First migration?

We’ve created a guide on scoping, planning, and managing the migration process for your use. If this is your first migration, we recommend reading this guide carefully. 

Prerequisites

There are many different versions of IMAP mail systems available. For this reason, we recommend running a trial migration on one or more mailboxes before the actual full migration project. Once the trial migration completes, check on the folder structure at the Destination to ensure that the directory structure is as desired. 

To run a trial migration, follow these steps:

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:

1. Purchase Licenses.
2. Create a Customer.
3. Apply Licenses.
4. Review Considerations.

Limitations

• Due to API limitations, IMAP migrations will only migrate mail items and we can only migrate mail items that are stored on the IMAP server. Verify that a copy of the mail remains on the server.
  • If there is no mail on the IMAP server and it's stored in a local PST, use the PST migration process.
  • If the data is stored in a local Outlook OST file (Outlook 2013 and Outlook 2016), export the mailbox to a PST and use the PST migration process.
• Only mail folders are migrated with this scenario. Contacts and Calendar items will need to be exported/imported manually.

• App password usage, MFA/2FA, and ADFS are not supported for the migration service accounts being used for this migration scenario.

• The maximum file size for migration through MigrationWiz varies by migration type and environment, but may never exceed 60GB.

Prepare the Source Environment

Please perform the following steps before starting a migration:

1. Test connectivity to the IMAP server through our connectivity test tool. Fill in the form and click the Test button.
2. Export the user list to a CSV file.

Besides, consider the following information:

• Administrator accounts with at least read rights can export a user list.
• If you do not have an administrator account, you will need to ask your IMAP host to provide you with a complete user list, in CSV file format.
• This CSV file will be used to bulk-add users into your MigrationWiz mailbox project.

Prepare the Destination Environment

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 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.

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. 

MigrationWiz Steps

Create a Mailbox Migration project

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.

1. Click the Go to My Projects button.
2. Click the Create Project button.
3. Select the Mailbox Project.
   

   Important

   For mailbox migrations, use the migration service credentials to access mailboxes. In most migration scenarios, this account must have full access rights to the Source mailboxes.

4. Click Next Step.
5. Enter a Project name and select a Customer.
6. Click Next Step.
7. Select endpoints or follow the steps below to create new endpoints.
8. Click Save Project.

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.

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.

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 Users

Add the user accounts that will be migrated to the project. MigrationWiz allows you to bulk import mailboxes into the system.

Use the Bulk Add option, and import from the CSV file that you prepared under the Prepare the Source section of this guide. 

1. Request credentials from each user.
2. Reset mailboxes to use the same password (this will lock users out).
3. Have MigrationWiz automatically request credentials from end users. Click here to learn more.

To request credentials from users: 

Enter the Source Email addresses in the Source Email column, and checkmark the I don't know the login name and password for the Source mailbox box (highlighted in blue with the below example). Users will then be requested to provide their credentials during the migration process.

For the destination users, you only need to enter the destination email address of each user as administrator credentials are used (supplied in the destination endpoint setup) for the import to the Exchange Online mailboxes.

Bulk Add

To import one or more mailboxes once you have gathered the necessary credentials: 

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.

Advanced Options

Support Tab

• FolderMapping="^INBOX/->" This will map folders to the root label on the Destination mailboxes, rather than under the inbox/label name. 

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.

Run Verify Credentials

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.​ 

Notify Users

Notify users that a migration is occurring. Send an email to all users telling them the time and date of the migration.

Run Migration

Pre-Stage pass

1. Select the users you wish to migrate.
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.

MX Record Cutover

Change over MX records on the DNS provider's portal.

Also, include the AutoDiscover (CName) setting.

1. Select the users.
2. Click the Start button from the top.
3. Select Full Migration.
4. Click Start Migration.

Run Retry Errors

Look through the user list and click any red "failed migration" errors. Review the information and act accordingly.

If problems persist, contact Support.

Unexpected Extra Arguments

If errors are listed in the MigrationWiz dashboard with the following error message: "Unexpected extra arguments to Examine Context: FolderNameWithQuote", then follow the steps below to add the support option flag AllowQuoteInFolder=1 at the item level, and run retry errors. 

Steps

1. Click the Edit Item icon to the right of the item that you wish to edit.
2. Under the Support section, enter the support option: AllowQuoteInFolder=1
3. Click Save Item.
4. Select the line item in your MigrationWiz dashboard.
5. Click Start.
6. Retry Errors.

Outlook Configuration

Users must create new Outlook profiles, set up their signatures again, and reattach any PST files that were attached to their previous profile.

Request Statistics

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

Related Topics

• EWS isn't supported when accessing Teams data 
• Retirement of RBAC Application Impersonation in Exchange Online
• Authentication Methods for Microsoft 365 (All Products) Migrations
  • Required Permissions for Performing M365 Mailbox and Archive Migrations 
  • Scoping Requirements for M365 Mailbox and Archive Migrations
• BitTitan - Data Security and Privacy Policy