PST to Microsoft 365 Migration Guide

This is the complete onboarding task flow for migrating PST files (Outlook Data File) into Microsoft 365 mailboxes.

MigrationWiz

MigrationWiz is a migration solution (not a synchronization solution) and will NOT propagate updates, deletes, or moves of the items previously migrated in the first migration pass because 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. For more information, visit Project Sharing in MigrationWiz. 

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.

For more information on how to set up a project using Azure Storage, read the Azure for MigrationWiz article.

The key difference for PST migrations, when compared to standard mailbox migrations, is that the PST files need to first be discovered and then uploaded to a secure Azure Storage account, before they can be migrated into the mailboxes on the Destination, using MigrationWiz.

Prerequisites

Review and meet the following requirements for PST files:

  • PST files need to be in Outlook 2003 (or later) format.
  • PST files cannot be corrupted. We do not provide an automated solution for repairing or migrating corrupted PST files. In case there are corrupted PST files, fix them before performing a migration.
  • If UploaderWiz is installed:
    • Windows Vista or later is required for desktops. Mac OS is not supported.
    • Installed .NET 4.6 or later.
    • Permission to run a command prompt as Administrator.

The key difference for PST migrations, when compared to standard mailbox migrations, is that the PST files need to first be discovered and then uploaded to a secure Azure Storage account before they can be migrated into the mailboxes on the Destination, using MigrationWiz.

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.
Purchase Licenses Create a Customer Apply Licenses Considerations

Purchase licenses by following the steps below:

  1. Sign in to your BitTitan account. 
  2. In the top navigation bar, click Purchase.
  3. Click the Select button and choose User Migration Bundle licenses.
  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.

Limitations

  • 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.

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.

Migrated Non-Migrated
PST Files from your Azure storage
  • Folders
  • Email
  • Contacts
  • Calendars
  • Tasks
  • Journals
  • Notes
PST BitTitan Storage 

PST Files are uploaded to BitTitan Storage using the UploaderWiz tool.

  • Folders
  • Email
  • Contacts
  • Calendars
  • Tasks
  • Journals
  • Notes

Prepare the Azure 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.

  1. Estimate Azure storage costs. This step is optional but is useful to provide the customer with upfront storage costs ahead of time. 
  2. Buy an Azure subscription, or use the free one-month trial. The trial option is only viable if you are performing a very small migration. 
  3. Create an Azure storage account. You will need to set up a STORAGE (General Purpose v2) account rather than a storage blob.
  4. Take note of the storage account name and the primary access key. (In Azure, from the storage screen, click Manage Access Keys at the bottom of the screen). These need to be entered into the MigrationWiz migration project when specifying the destination settings. 

To create the Azure storage account, follow the steps below:

  1. Visit the Azure portal.
  2. Click Storage accounts.
  3. Click Create.
  4. Select the Subscription and create a new Resource group or use a current one.
  5. Name the Storage account.
  6. For Region, select a geographic region for the storage account.
  7. For Performance, select Standard general-purpose V2 account.
  8. In the Redundancy field, select Locally-redundant storage (LRS).
  9. Click the Review button.
  10. When the validation ends, click the Create button.
  11. Once the deployment of the storage account is complete, click the Go to resource button or open up the home page for the new storage account.
  12. In the Security + networking section of the left sidebar, click on Access Keys.
  13. On a notepad, copy the Storage account name and the key1 and save them.

Now the storage account appears in the storage list.

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 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.

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.

Set up Accounts in Microsoft 365

Set up accounts on Microsoft 365 and assign licenses. These can be created in several ways:

Prepare the Tenant to Send & Receive Large Items

We do not impose any limit on item/attachment sizes. However, large items/attachments can fail to migrate because of external factors.  There are two considerations:​

What is the maximum attachment size allowed by the Destination system? 

  • Most email systems impose size limits. For example, if the Destination system has a 30MB limit, any item/attachment larger than 30MB will fail to migrate.

What is the connection timeout for the Source and Destination system? 

  • ​​For security reasons, most email systems close opened connections after a predetermined amount of time. For example, if the Destination system only has 512Kbps of network bandwidth and closes connections after 30 seconds, we may be unable to transfer large items/attachments before the connection is closed.

MigrationWiz automatically makes multiple attempts to migrate large items. Upon completion of a migration, you may resubmit it in error retry mode to try to migrate failed items. This is always free of charge.

When migrating from or to Office 365 use the steps provided here to increase the Max Send and Max Recieve quotas, Change message size limits in Office 365.

Discover PST Files and Upload to Azure

Discover PST files on the network, and upload them into Azure.

MigrationWiz Steps

Create a Personal Archive Migration Project

  1. Click the Go to My Projects button.
  2. Click the Create Project button.
  3. Select Personal Archive as the migration type.
  4. Click Next Step.
  5. Enter a Project name and select a Customer.
  6. Click Next Step.
  7. Create or select your source and destination 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.

Source Endpoint Destination Endpoint

Create your source endpoint by following the next steps:

  1. Click Endpoints.
  2. Click Add Endpoint.
  3. Select PST.
  4. Enter Storage Account Name and Access Key in the fields provided. When entering the Azure Storage Account Name for the source endpoint, only numbers and lowercase letters can be used. If you enter an upper case letter, your migration will fail.

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 'Region closest to the Destination Tenant' 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 administrator 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.

Advanced Options

The following sections describe the tabs available for Advanced Options in this kind of migration.

Support Tab

Consider that each Support Option includes the "=" character and is to be entered under the Support tab in the section named Support Options.

Add additional blank fields for new Support Options by clicking on the "+" button. In case you want to delete a field click the trash can icon.

AO Support Tab.jpg

Optional Settings

  • PSTCustomEndpointSuffix=Azure URI This advanced option is only needed when uploading your PST files to a specific Azure data center, using the UploaderWiz optional parameter of azurelocation=gov, or ger. The Azure URI needs to be changed to one of these values:
    • cloudapi.de (Germany)
    • usgovcloudapi.gov (government)
  • Folder Mapping Folder mapping is optional, but you can control the mapping of folders on the destination by using regular expressions. Read the Folder Filtering & Mapping in MigrationWiz article for more information.

    Important

     By default, MigrationWiz mirrors the folder structure that exists on the Source when migrating to the Destination. When a migration starts and you are taking the default folder mappings (that is, a single folder at the root), MigrationWiz creates the Destination folder based on the item type of the first item migrated. If the first item is a calendar item, then the Destination is mapped to the root of the calendar folder. You can control this by migrating item types in batches (mail items, calendar items, etc.), with each item type migrated in a separate migration pass.

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.
Duplicate Support Option.png

Source/Destination Tab

  • Set the bucket name to "migrationwiz". If you are using your own Azure storage and uploaded your PST files into a container that has a different name, change the bucket name to "migrationwiz". If the container name and bucket name do not match, you will get an error when trying to import your PST files.
  • Under Destination, choose whether to ingest the PST files into mailboxes or archives.

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.

Import PST files

Import PST files into the MigrationWiz PST archive project.

  1. Click the Autodiscover Items bar.
  2. Click the Start Autodiscover button.
  3. Once the PST files have been discovered, click the green + Import Items.
  4. If 0 items are discovered, a common mistake is that the Source/Bucket Name under Project Advanced Options has not been set to the correct Azure container name.

Choose Destination Mailbox

Choose which Destination mailbox to inject each PST file into.

The owner's email address should be displayed under the "Destination Email" column.
If change.me@bittitan.com is displayed as the Destination email address instead of the actual owner's email address, click the Edit Item (pencil icon) to the right of the row. Then, under the Destination Email Address field, enter the mailbox that this file will be ingested into.

If you have multiple PST files to migrate into a single mailbox, click the pencil icon next to the individual migration item. Then, under Source PST Path, click the Add button (the +) to add the additional PST path(s).

Run Verify Credentials

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

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

Start migration

  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.

Post Migration

Optional (does not apply to Microsoft storage): Delete the Azure blob container that was created during the upload to Azure. This will prevent incurring post-migration Azure costs for these containers. Be careful and delete only the container created for this migration project.

Was this article helpful?
0 out of 4 found this helpful