IMAP to Microsoft 365 Migration Guide

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

App passwords are not supported for the Microsoft 365 endpoint. 

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.

There are some tools and resources that will make the migration easier.

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.

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. 

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

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

Only mail folders are migrated with this scenario. Contacts and Calendar items will need to be exported/imported manually.

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:

  1. Sign in to your MigrationWiz account.
  2. Click on your migration project. If you haven't created a project, create a project (following the steps laid out in the Create a Mailbox Migration Project below) and add a user to that project.
  3. Select the user for whom you wish to perform the trial migration.
  4. Click on Start.
  5. From the drop-down list, click on  Trial Migration .
  6. Click on Start Trial Migration.

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.

Prepare the Source Environment

  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.
  • 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

  1. Set up user accounts on the destination Office 365 tenant and assign licenses. These can be created in several ways. We have a few options listed below:

  2. Create an administrator account in Office 365 to be used for migration or use the global admin account for the tenant. The minimal service account requirements are full access rights to the mailbox and impersonation rights. We recommend using impersonation over delegation because it is Exchange Online. For specific steps to set impersonation manually, see Impersonation and Delegation.

Modern Authentication Requirements

The steps listed in the Obtain Client and Tenant ID Settings for Mailbox and Exchange Online Migrations section of the Authentication Methods Migrations KB 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.

MSPComplete Steps

Create Customer

  1. Click the Add button in the top navigation bar
  2. Click the Add Customer button on the All Customers page
  3. In the left navigation pane, select the appropriate workgroup and then click All Customers.
  4. Click Add Customer.
  5. Enter the new customer’s information in the Add Customer form. Primary Email Domain and Company Name are required. The rest are optional.
  6. Click Save.
  7. Repeat steps 1 through 4 for each customer you want to add. 

Purchase licenses

We recommend that you purchase the User Migration Bundle license for this migration scenario. User Migration Bundle licenses allow multiple types of migrations to be performed with a single license. They also allow DeploymentPro to be used to configure Outlook email profiles. For questions on licensing, visit MigrationWiz Licenses

To purchase licenses

  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.

Apply for licenses

  1. Select the correct workgroup on the top of the left navigation pane. This is the workgroup that the customer and migration project were created under. Your account must be part of the workgroup if the project was not created under your account.
  2. On the left navigation pane, click Customers.
  3. Click the customer that employs the user to whom you want to apply for a User Migration Bundle license.
  4. Click the Users tab at the top of the page.
  5. Check the box to the left of the email for the user(s) to whom you want to apply for a license.
  6. Click the Apply User Migration Bundle License button at the top of the page. It is recommended that users be added to the Customer page with the vanity domain. Then have the User Migration Bundle Licenses applied, before editing to show the .onmicrosoft domain, if the .onmicrosoft domain will be used for the migration.
  7. If there is at least one unassigned User Migration Bundle license available for each selected user, click Confirm. 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.

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. 

  1. Click Next Step.
  2. Enter a Project name and select a Customer.
  3. Click Next Step.

Endpoints

Endpoints are now created through MigrationWiz, rather than through MSPComplete. The steps for this section outline how to create the endpoints in MigrationWiz.

If you are selecting an existing endpoint, keep in mind that only ten endpoints will show in the drop-down. If you have more than ten, you may need to search. 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.

You may either use existing endpoints or create new ones. 

Create a new source endpoint

  1. Click Endpoints.
  2. Click Add Endpoint.
  3. Select IMAP.
  4. The server name should follow the format: imap.example.com

  5. Enter server port. As a general rule, the server port will be either 143 or 993 (if using SSL).

  6. If you are using SSL, add a checkmark next to Use SSL.

Create a new destination endpoint

  1. Click Endpoints.
  2. Click Add Endpoint.
  3. Enter endpoint name.
  4. For the endpoint type, select Office 365.
  5. Fill in the required fields.
  6. Complete the Application (client) ID and the Directory (tenant) ID fields.
    Destintation Settings.png

Important

When configuring the destination endpoint, do not forget to complete the client ID and the tenant ID fields for the Destination endpoint, otherwise, you cannot save your project migration.

Once the information has been provided for both, the source and/or destination endpoint, and the customer selects Save and Go to Summary, MigrationWiz performs an endpoint validation check for the Microsoft 365 endpoint.

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. 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. 

Important

Administrator credentials are not supported for this type of IMAP endpoint
  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.

Bulk_Add_IMAP.png

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.

Add Advanced Options

Recommended Options

Under Source / Destination:

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

Optional but recommended, under Support/Support options:

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

Default Options

The client and tenant ID fields for source in the Support tab of the project’s Advanced Options, are view-only fields. This means that you cannot edit or remove them from the support options page. To edit them,  you need to edit the project.

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

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.

 

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