How to migrate from Microsoft 365 tenant to another tenant?

Office 365 tenant to tenant migration

Steps to migrate from Office 365 tenant to tenant

EdbMails software for Office 365 tenant migration

Office 365 to Office 365 tenant migration refers to the process of moving data and services from one Office 365 tenant to another. The migration can be either within the same organization or between two different organizations. Business and organizations have a requirement for tenant to tenant migration in Office 365 during company acquisitions and mergers. The migration involves assessing your current environment and moving the mailboxes, folders and mailbox data. As a result, migrating large data from the source to the target is often challenging without proper guidance.

EdbMails Office 365 migration software is one such solution that significantly simplifies the tenant to tenant mailbox migration compared to the Microsoft native migration method. The application can migrate all of your mailbox data, emails, messages, appointments, folders, contacts, calendars, tasks, journals, permissions, user folders, public folders, shared and archive mailboxes and help you migrate an Office 365 tenant to another. In this Office 365 migration guide we describe the planning, pre and post migration tasks along with the actual migration.

Office 365 tenant to tenant migration

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Office 365 Migration with same domain Office 365 to Exchange migration Public folder to Office 365 migration Archive mailbox to Office 365 migration Export PST from Office 365

Office 365 tenant to tenant migration plan

Planning is the most important aspect of the migration. A good plan saves time and makes the operation a smooth and stress-free one. Here is a checklist of the most important points to consider for o365 mailbox migration.

Prepare a complete inventory of items that you want to migrate.
Take a complete backup of your mailbox inventories and remove unused and unwanted mailboxes from the source.
Determine the size of the mailbox data and number of mailboxes to migrate.
Determine if you want to migrate Public folder and Shared mailboxes along with the user mailboxes.
Communicate the plan and the changes to your end users.
Prepare the domains and required Active Directory services on the target.
Create and prepare the mailboxes and Public folders on the target Office 365 server.
Assign suitable licenses to the mailboxes.
Ensure you have enough network capacity and bandwidth to migrate.
Consider the throttling and message size limits on Office 365.
Perform a test Office 365 migration before you start the actual migration.
Start the migration, verify the endpoint and add DNS records.
Create new Outlook profiles and check if you are receiving mails correctly.
Remove the permissions and licenses on the source Office 365 tenant.

I. O365 tenant to tenant migration prerequisites

On the source Office 365

Decide the migration path you want to take depending on your source and target environment.

Current environment and migration requirement	Migration approach	How does the migration take place?
You want to migrate Office 365 tenant to another in a single event and in a limited time frame.	Cutover migration	In this approach, you set up your target Office 365 tenant and migrate everything in a single sitting. Suited for large mailbox migration
You want to perform Exchange online to Office 365 migration in batches	Staged migration	In this approach, you migrate your mailboxes and mail data in stages and transfer the required or the most recent data first followed by the others.
You have an on-premises Exchange server that coexists with Office 365 cloud	O365 Hybrid migration	In this approach, you migrate Exchange online to Office 365 while also migrating from the Hybrid Exchange server

Ensure that you meet the network and bandwidth requirements for the migration. See network and migration planning, performance factors and best practices for Microsoft 365 migration.
Assign the Organization Management role group in Exchange online to the admin user on both the source and the target. It is an elevated permission that is required to migrate Public folders and In-Place Archive.
Set the impersonation rights for the admin account in Office 365 to migrate mailboxes on behalf of other users in your organization.Verify if the source and target admin account in general has the following management roles assigned:
1. ApplicationImpersonation
2. View-Only Configuration
3. View-Only Recipients
4. Public Folders
5. User management administrator/Global administrator
Check if the Global admin account with the management roles has a valid and non-hidden mailbox on the source and target server.

On the target Office 365
1. Prepare your target Office 365 tenant. See tenant roadmap for Microsoft 365.
2. Purchase an Office 365 licensing plan specific to your needs. You can also sign up for a 30 day free trial and decide to go with a suitable one later. Compare Office 365 business plans and Compare Office 365 enterprise plans
3. Before you migrate from Office 365 tenant to another, ensure that you create mailboxes for your users in your organization and assign suitable licenses to them.
4. If you plan to migrate the source Public folders to Public folders on Office 365, ensure that you create and configure the Public folder mailboxes on the target server.
5. If you plan to migrate In-Place archives from one tenant to another, enable the archive mailbox on both the source and target. See steps to enable online archive in Office 365.
6. Assign the Organization Management role group in Exchange online to the admin user. It is an elevated permission that is required to migrate Public folders.
7. Ensure that you set the impersonation rights on Office 365 for the admin account to migrate mailboxes on behalf of other users in your organization.
8. If you have a custom email domain from the source to which you want to receive emails after the migration, you must add and verify the custom domain on Office 365.
  Steps to add a custom domain to Office 365 and steps to add DNS records to connect your domain.
9. If you are using Active Directory Federation Services, you must configure a new domain on the target tenant for AD FS.
10. Configure Office 365 to send and receive large messages
  Follow the steps to increase the message size on Office 365 to 150MB.

II. How to perform Office 365 tenant migration?

The following methods can help you migrate tenant to tenant in Office 365

Office 365 cutover migration
Batch or staged migration
Hybrid migration to Office 365

Steps for tenant to tenant Office 365 migration

Step 1: Download and install EdbMails Office 365 migration software
- Download EdbMails and install the application on the source computer. The application is compatible with Windows 11, 10, 8.1, 8 and 7.
  See a detailed list of EdbMails system requirements for o365 to o365 migration.
- Launch the application and click 'Login' or 'Start Your Free Trial'.
- Select the option for mailbox migration to Office 365 as shown
Note: If the Standard folders (such as Inbox, Calendar, Contacts) on your source tenant mailboxes are initialized with a different language, follow the details in the link to migrate these folders to the respective system folders on the target (destination) server.
For Instance: If your source Inbox folder is named 'Boîte de réception', which is in French language and you migrate this folder directly to the destination server, then by default it will not be mapped to the 'Inbox' folder on the target server. In order to map the folder with the french name to the respective folder, change the regional settings on the target server to match that of your source mailbox folder language (in this case, it is French).
Steps to change the language and regional settings on Office 365
Step 2: Connect to the source Office 365 as Global Administrator
In the Connect to Office 365 (Source) window, select the authentication method as Auto or Manual registration for modern authentication and the connection method as Mailboxes, Public folder or Archive Mailbox. Enter the global administrator credentials to authenticate.
Connect to Office 365 server using secure modern authentication

After you authenticate and log in successfully, select one of the methods to load the mailboxes. You can also load and migrate the mailboxes using a CSV file.
Step 3: Select the mailbox items and connect to the target Office 365
1. EdbMails displays a list of mailboxes from the source Office 365 tenant.
2. Select the mailboxes and folders that you want to transfer.
3. Click 'Migrate to Office 365' to set up the connection with the target server.
Tip: If this is the first time you’re migrating with EdbMails, the migration is a full migration. On subsequent migrations from the same source to the target, the migration is incremental.
Step 4: Connect to the target server as Global Administrator
EdbMails supports both modern and classic authentication. Connect to the target tenant by selecting Auto or Manual registration for modern authentication and the connection method as Mailboxes, Public folder or Archive Mailbox.
Connect to Office 365 server using secure modern authentication
Tip: The mapping activity in EdbMails can automatically match and map the mailboxes and folders between the source tenant and target. This activity saves time when you’re migrating a large number of mailboxes.
Step 5 : Start the migration from Office 365 tenant to tenant
Start and monitor the mailbox migration from one tenant to another after you complete the mailbox mapping. Finally, verify the count of migrated emails, folders and mailbox items with EdbMails text-based log report.

Steps for tenant to tenant O365 staged migration

The staged migration with EdbMails involves migrating the newest mailbox data to your Office 365 tenant in the first stage and gradually migrating the remaining items in stages or over weeks.

Step 1: Install EdbMails and connect to the source Office 365 tenant
Download and install the application and select Office 365 migration. In the connection page, select Auto Registration and connect to the source Office 365.
Step 2: Select the mailbox data to migrate to the target Office 365
1. After a successful login, EdbMails displays a list of mailboxes and folders.
2. Select the mailboxes and folders you want to migrate and click 'Migrate to Office 365'
Step 3: Prepare your mailbox data for Office 365 staged migration
EdbMails provides the following additional options to help you customize the staged O365 tenant migration and filter emails based on the Date and other conditions.
1. Additional Include and Exclude Filter Options.
2. Filter emails by Date: Migrate to Office 365 by applying the Date filter
3. Filter emails by Size: Exclude emails or attachments larger than a specified size.
4. Filter emails by domain: You can filter the emails for migration based on the Sender Address or email domain.
Step 4: Connect to target server as a Global Admin user
EdbMails supports both modern and classic authentication. Connect to the target server by selecting Auto or Manual registration for modern authentication and the connection method as Mailboxes, Public folder or Archive Mailbox.
Connect to Office 365 server using secure modern authentication
Step 5: Map the mailboxes and start the staged Office 365 migration
The mapping activity in EdbMails can automatically match and map the mailboxes and folders between the source and target server. Start and monitor the migration and verify the count of migrated emails, folders and mailbox items with EdbMails text-based log report.

Tenant to tenant Office 365 Hybrid migration

If you plan to migrate from a coexisting on-premises Exchange and Office 365 environment to the target Office 365, then a Hybrid migration is the best solution.

See Office 365 Hybrid migration steps by using EdbMails

If your mailboxes are in a Hybrid environment, it is not possible to migrate Public folders directly to Office 365. Refer to this workaround solution to migrate Public folders in a hybrid environment.

III. Tenant to tenant Post-migration Activities

Step 1: Update the MX records to point to Office 365
Add the existing domain to the target Office 365 and if you haven’t updated the DNS records previously, you must change the MX records to enable email flow and receive messages. In addition to this task, configure the Autodiscover record to enable Outlook to connect to the migrated mailboxes.
Step 2: Clear the Auto-Complete list in Outlook
See manage suggested recipients with Auto-Complete.
Step 3: Remove the old Office 365 subscription plan
- Ensure you have the latest version of Outlook installed to avoid compatibility issues.
- Configure the Outlook profile for each user in your domain if Outlook has problems connecting to Office 365 mailboxes.
- Configure the new server settings, such as the server address, username, and password in Outlook.
- Test email flow to ensure that your users are able to send and receive emails.
Step 4: Remove the old Office 365 subscription plan
After the migration is successful and you have verified the mailbox data, remove the Office 365 subscription plan from the source and any domains associated with it.

IV. Office 365 migration troubleshooting

See the troubleshooting solutions for Office 365 and Exchange migration. For more information related to EdbMails application, see frequently asked questions.

Benefits of EdbMails for Office 365 tenant migration

Zero downtime and zero data loss O365 migration
Migrate SharePoint, OneDrive and Microsoft Teams data.
EdbMails enables you to migrate from Rackspace to Office 365 and perform tenant migration from Godaddy to Office 365
Advanced folder and filter settings to selectively migrate the data.
Easy Exchange online migration with no PowerShell scripts and cmdlets
EdbMails does not modify the source or the target data and preserves the data consistency.
Support for secure modern authentication for Office 365.
A versatile solution for Office 365 Group migration and Public folder to Shared mailbox migration.
World-class and free 24x7 support to assist you with the tenant to tenant migration.