Zimbra 6+ to Microsoft 365 using Graph API Migration Guide

Notes

  • Although present in the UI, BYO App using Client Certificate is currently unavailable. We are working on a resolution for this issue at this time.
  • GoDaddy-Hosted Office 365 is currently not supported with the Graph Endpoints at this time.
  • Due to Graph API limitations at this time, Archived Mailboxes migrations are not fully supported using the Graph API. If your migration involves Archived Mailboxes, you should use EWS (Zimbra Migrations) to perform your migration project until the Graph limitations are resolved by Microsoft and we are able to extend support for this scenario using the Graph API.

This is the complete onboarding task flow for migrating mailboxes from Zimbra (version 6 and later) to Microsoft 365 using Graph API. 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 Which Migration License Do I Need?.

To use your license by following the next steps:

  1. Review Considerations.
  2. Purchase Licenses.
  3. Create a Customer.
  4. Apply Licenses.
ConsiderationsPurchase LicensesCreate a CustomerApply 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 Which License Do I Need? guide.

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, SSO, and ADFS are not supported for the Microsoft 365 endpoint. 
  • Due to Microsoft limitations, using Delegate Permissions with Graph API is not supported at this time. Only Application Permissions can be used.
  • Pinned/Flagged Emails are migrated but not Pinned/Flagged in the destination environment.
  • Threading (email messages that belong to the same conversation) is not supported and will require Manual implementation. 
  • Delegate-level calendar access isn't supported by Microsoft Graph. It's automatically downgraded to Free/Busy-only.
  • Archive Mailbox as a destination is currently not supported. Support for this option is planned for a future release.

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.

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 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.

  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 KBs listed in the Exchange Online Authentication options using Graph API section will help you configure the source tenant when using Microsoft 365 with the Microsoft Graph API. A Global Administrator account is required to consent to the BT app or create and consent to the BYO app, since the Entra app's permission types require global admin approval.

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

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

Service Account Password

Before migrating, ensure that the service account password does not contain any commas. If it does, update the password before starting the migration process.

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.

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

  • InitializationTimeout=8 This increases the initialization timeout window to eight hours. This value is in hours, up to a maximum of 100 hours. Values above 100 are in milliseconds. For example:​
    • InitializationTimeout=2 will increase the timeout to 2 hours.
    • InitializationTimeout=8 will increase the timeout to 8 hours.
    • InitializationTimeout=14400000 will increase the timeout to 4 hours.
    • InitializationTimeout=21600000 will increase the timeout to 6 hours.

Required Settings

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

Bulk Load

To upload a large list of Advanced Support options, see the Bulk Load - Advanced Options when Migrating Mailbox projects using Graph API for additional guidance.
 

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.

Run Verify Credentials

  1. ​Sign in to your MigrationWiz account.
  2. Open the Project containing items to validate.
  3. Choose the items 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.

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