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.
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 sharing migration projects across a Workgroup. When the Project Sharing feature is turned on, all Agents besides those who are Inactive can view all migration 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:
- 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
Consider the following limitations for this type of migration.
- The following guide applies to Zimbra 6+.
- We are not able to support migrations with two-factor or multifactor authentication.
- The password for the migration service account cannot contain commas. Using a comma in the password may cause the migration to fail.
- App password usage, MFA/2FA, and ADFS are not supported for the Microsoft 365 endpoint.
Migrated Items
Below you can find a list of migrated and non-migrated items. We are constantly working to create a better migration experience for you so these items may change over time.
You can find the migrated items for this migration type in the following list.
- Inbox
- Folders
- Contacts
- Calendars
- Tasks
You can check the non-migrated items for this migration type in the following list.
- Zimbra Tags
- Rules
- Zimbra Archive Mailbox
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.
- Open Zimbra Admin.
- Select Account.
- In the Search box, type the domain name to be exported.
- On the Toolbar Zimbra Admin, select the Download button.
- 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 a migration service 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.
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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.
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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
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.
Set up Accounts in Microsoft 365
Set up accounts on Office 365 and assign licenses. These can be created in several ways:
- Manually, one at a time.
- By bulk import, via CSV file.
- By PowerShell script.
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
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.
- Click the Go to My Projects button.
- Click the Create Project button.
- 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.
- Click Next Step.
- Enter a Project name and select a Customer.
- Click Next Step.
- Select endpoints or follow the steps below to create new endpoints.
- 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.
Create your source endpoint by following the next steps:
- Click Endpoints.
- Click Add Endpoint.
- Select Zimbra 6.5+.
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Enter Zimbra server URL.
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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.
- Click Add.
- Click Next Step.
Create your destination endpoint by following the next steps:
- Click Endpoints.
- Click Add Endpoint.
- Enter endpoint name.
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Select Microsoft 365 for the endpoint type.
- Select one of the following credential options.
- Provide Credentials, the form expands to show more fields for username and password. MigrationWiz uses the credentials to access the service chosen. In most cases, you must provide credentials for the migration service account on those services, as this will enable MigrationWiz to have full access to the cloud service.
- Do not Provide Credentials, MigrationWiz requests credentials from end users before a migration can be started. This may slow your migration, as you are now dependent on end users to provide these credentials.
- Click Add.
- Complete the Application (client) ID, the Directory (tenant) ID, and the Client Secret fields.
- Click Next Step.
- Click Save and Go to Summary.
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.
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 migration service account. 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.
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.
- Sign in to your MigrationWiz account.
- Choose the project for which you want to perform the bulk import.
- Click on Add.
- Click on Bulk Add.
- 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.
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 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.
Run Verify Credentials
- Sign in to your MigrationWiz account.
- Open the Project containing items to validate.
- Choose the items to validate.
- Click on the Start button in your dashboard.
- 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
- Select the users you wish to migrate.
- Click the Start button from the top.
- Select Pre-Stage Migration.
- Under the Migration Scheduling section, from the drop-down list, select 90 days ago.
- 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:
- Set up Zimbra mail forwarding.
- Set up Office 365 mail routing.
Full pass
- Select the users.
- Click the Start button from the top.
- Select Full Migration.
- 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.