Zimbra 6+ to Microsoft 365 Migration Guide

This is the complete onboarding task flow for migrating mailboxes from Zimbra (version 6 and later) to Office 365. MigrationWiz no longer supports TLS 1.0.  TLS 1.2 is now required. Verify the TLS version and update, if necessary, before migrating.

App password usage, MFA/2FA, and ADFS are not supported for the Microsoft 365 endpoint. 

MigrationWiz

MigrationWiz is a migration tool, not a syncing tool. If changes are made at the source after migration, they do not sync to the destination, nor do the changes made at the destination sync to the source. We do not have “live” monitoring of changes (as with a sync agent) and 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 created a guide on scoping, planning, and managing the migration process for your use. If this is your first migration, we recommend carefully reading this guide.

Prerequisites

It is important to highlight and meet the following prerequisites for a smooth migration project.

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

  • The following guide applies to Zimbra 6+
  • We are not able to support migrations with two-factor or multifactor authentication. 

Migrated Items

What items are and are not migrated?
Migrated Not Migrated

You can find the migrated items for this migration type in the following list.

  • Inbox
  • Folders
  • Email
  • Contacts
  • Calendars
  • Tasks

Prepare the Source Environment

Users must enter usernames on the Zimbra side, even when using an admin account.

Export Users

Export the list of users to a CSV file. This will be used when adding users to your MigrationWiz mailbox project later in the migration.

  1. Open Zimbra Admin.
  2. Select Account.
  3. In the Search box, type the domain name to be exported.
  4. On the Toolbar Zimbra Admin, select the Download button.
  5. Save the CSV file generated.

Split Large Folders

Zimbra will exhibit poor migration performance for folders with several numbers of items. Please, split up folders to avoid performance issues.

Calendar folders can be slower to migrate when the data is complex. For example, recurring calendar meetings result in increased calendar events.

Prepare Admin Credentials

Guarantee that you have admin credentials available for use during migration. If selecting to assign the admin role through the Zimbra administrator portal instead of the below commands, the user must be granted Global Administrator. Assigning just an Administrator will not work.

You can prepare your Admin Credentials by using one of the following options:

  • Use existing credentials.
  • Create a new admin account for migration. This will create an additional admin account with the password of 'test123':
    zmprov ca testadmin@domain.com test123 zimbraIsAdminAccount TRUE
  • Transform a normal existing user account into an admin account (in this example future-admin will become an admin):
    zmprov ma future-admin@domain.com zimbraIsAdminAccount TRUE

Test Mailbox Access

Accessing the SOAP web services is needed for migration, so corroborate that the necessary ports are open to connect to the Zimbra server. There are two modes to connect to a Zimbra server, Regular and Admin User mode.

  1. In regular user mode, we need access to SOAP web services, which are typically the following:
    • ​On port 80 if it is an HTTP connection.
    • On port 443 if an HTTPS connection.
  2. In admin user mode, we also need access to SOAP web services, typically:
    • ​On ports 80 and 7071 when the Zimbra URL is HTTP.
    • On ports 443 and 7071 if the Zimbra URL is HTTPS.

You must connect using both ports (ports for regular user mode and admin user mode). Some operations will go over the admin port, while others the regular port.

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 mailbox, and archive mailbox. Use a Global Administrator for the configuration steps.

Please review the documentation before preparing the source.

Create an Administrator Account

Create an administrator account in Microsoft 365 to be used for migration or use the global admin account for the tenant. The administrator account must have full access to the user mailboxes, have the required API Permissions, or be granted impersonation rights.

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.

However, you can still use the BitTitan impersonation approach if you already have a service account with the Application Impersonation role already assigned. Microsoft is phasing out RBAC Application Impersonation in Exchange Online and no longer allows the assignment of this role to new accounts.

Set up Accounts in Microsoft 365

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

Prepare the Tenant to Send and 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 will automatically make 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.

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 must 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.
  4. Select endpoints or follow the steps below to create new ones.
  5. Click Save and Go to Summary.

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 Zimbra 6.5+.
  4. Enter Zimbra server URL.

  5. Click the Provide Credentials radio button, and enter the admin account credentials. These are either your existing admin credentials or the credentials for the account that was created under the "Prepare the Source Environment" section of this guide.

  6. Click Add.
  7. 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.

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

MigrationWiz displays a dropdown to select the Preferred Region of the Tenant at the destination endpoint. This value updates the Preferred Region of the Destination Tenant field in the project's Advanced Options, and vice versa. You will notice that both values are always the same.

The Region of Destination Tenant feature optimizes the migration performance and speed when choosing the region closest to the destination tenant.

Tip

You can find the region of your destination tenant directly in the Microsoft Entra admin center by going to Identity > Overview > Properties, and using the Country or region or the Data location.

Country or region.png

For more information on this topic, review this article.

Warning

If you do not complete this field you will not be able to save your project and the “This field cannot be left blank.” error will appear.

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. MigrationWiz allows you to bulk import mailboxes into the system.

Important

The Username of the source mailbox needs to be for the user mailbox being migrated and not the Zimbra administrator account.

Use the Bulk Add option and import from the CSV file, you can use the one prepared under the Prepare the Source section. 

Import one or more mailboxes by following the next steps.

  1. Sign in to your MigrationWiz account.
  2. Choose 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

Required Settings

  • ZimbraCalendarExpandInstances=1 By using this option, you can expand calendar instances, in case Zimbra is missing calendars in the migration.

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

Performance Tab

Maximum concurrent migrations. We recommend setting this to a meager value, such as 5, to ensure that server utilization does not go above 80%.

  • If the Source Zimbra server is running low on resources, it can result in an email being migrated as blank.
  • If the Source server has enough resources, set this parameter based on the bandwidth guideline of three (3) mailboxes per 1Mbps bandwidth.
    Therefore, for example, if there is a 10Mbps connection, we recommend setting the maximum concurrent migrations parameter to 30. In case the Source server has limited available resources such as low memory or high CPU usage, we suggest setting a lower value to prevent overloading the server with requests.

Source/Destination Tab

For this type of migration, set the project to use impersonation at the Destination. Checkmark the Use impersonation at Destination box. 

Run Verify Credentials

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

Once complete, you can check the verification results 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.

If you are migrating in batches and coexistence is required, you will not be cutting over the MX records until your final batch of users has been migrated, and you must perform two extra steps:

Full pass

  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.

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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