Migrate Emails from Office 365 Tenant to Tenant for IT Teams
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Written By
Aradhya Jain -
Approved By
Shivam Rathore -
Updated on
August 7th, 2026 - Read Time
7 minutes
User Query: “Our company recently merged with another organization. We have around 300 Microsoft 365 mailboxes that need to be moved to a new tenant. We want to migrate emails without losing folder structure, attachments, or mailbox data. Is there a secure way to migrate email between two Microsoft 365 Tenants without affecting users?”
Introduction: Microsoft 365 has emerged as the preferred email system for all companies irrespective of their sizes. With growing companies, consolidations, and restructuring, it becomes important to migrate users between two Microsoft 365 tenants. Each tenant is unique in terms of identity, users, policies, and licensing. This guide explains the best methods to migrate emails from Office 365 tenant to tenant. It includes the manual method and a professional DRS Softech O365 Tenant to Tenant Migration Tool.
What Is Migration From One Tenant to Another?
Office 365 tenant can be seen as a specific environment in Microsoft Cloud that contains a unique domain, users, licensing, mailboxes, and so on. If a company decides to transfer email, calendars, contacts, and all Exchange Online data to another tenant, that would be considered a tenant-to-tenant migration.
Why Migrate Emails Between Tenants?
- Mergers and acquisitions: Two companies combine, and their email systems need to merge all emails.
- Business Rebranding: Organizations sometimes change their company name or domain. Creating a new Microsoft 365 tenant with the new branding requires migrating existing mailboxes.
- Tenant consolidation: Large enterprises may have multiple Microsoft 365 tenants created over time. Combining them into one tenant improves collaboration and simplifies user management.
- Compliance or regional requirements: Some companies migrate to a new tenant to implement updated security policies, compliance standards, or access controls.
Manual Method to Migrate Emails from Office 365 Tenant to Tenant
Microsoft provides a manual method that helps to migrate data from One Tenant to another. This method is only available for users who have Microsoft 365 Admin Center, Exchange Admin Center, and PowerShell.
1st Step: Prepare the Source and Destination Tenants
- Validate both the tenants of Microsoft 365.
- Confirm the destination tenant has an Exchange Online license.
- Create or synchronize the user accounts in the destination tenant.
- Validate the domains to be utilized post-migration.
2nd Step: Migration between Office 365 tenants
- Set up an organization relationship between the source and destination tenants.
- Configure the required mailbox migration settings in Exchange Online.
- Map each source mailbox to its corresponding destination mailbox.
- Create a migration batch using the Exchange Admin Center or PowerShell. Select the mailboxes to migrate and start the migration process.
- Track the migration progress through the Exchange Admin Center. Review migration reports and resolve any errors that appear during the process.
3rd Step: Complete the Migration
- Complete the migration batch.
- Then, update DNS records if required.
- Verify that users can access their new mailboxes.
- Confirm that emails, contacts, calendars, and folder hierarchy have been migrated correctly.
Limitations of the Manual Method
- It requires advanced knowledge of Microsoft 365 and PowerShell.
- This method involves multiple configuration steps before migration.
- Migrating large numbers of mailboxes can be time-consuming.
- Does not provide a simple, centralized interface for managing the entire migration.
- Some settings, permissions, and configurations may require manual reconfiguration after migration.
Professional Tool to Migrate Emails from Office 365 Tenant to Tenant
For a batch tenant-to-tenant migration, use the DRS Softech Office 365 Tenant to Tenant Migration Tool. This tool migrates all important data from One Tenant to another without any data loss. Designed with Microsoft Graph APIs and Modern Authentication, this software performs a 100% secure migration. Helpful in several scenarios, including Mergers and Acquisitions (M&A), Large-Scale Enterprise Tenant Migration, & Migration and Deduplication in a Single Solution. Using this tool, you can migrate:
- Migrate Exchange Online Mailbox to Exchange Online: Emails, attachments, contacts, calendars, shared mailboxes, and archive mailboxes.
- SharePoint Online: SharePoint sites, document libraries, folders, files, and lists.
- OneDrive for Business: Personal OneDrive files and folders, including the latest file versions.
- In addition to migration, the software includes built-in Mailbox, SharePoint, and OneDrive deduplication.
Quick Steps to Migrate Email Between Two Microsoft 365 Tenants
|
Steps |
Description |
|
Choose Module to Migrate |
After downloading, click Copy and choose Mailbox, SharePoint, or OneDrive Migration. |
|
Authentication Method |
Select the source Microsoft 365 Authentication Method from Modern Authentication or Admin Impersonation. |
|
Select Users ID & Mapping |
Choose the mailboxes, SharePoint sites, or OneDrive accounts you want to migrate. Map source and destination users. |
|
Advanced Features and Export |
Apply the advanced features and filters to migrate. Click Start Export. |
Note: For detailed steps, check the software guide of DRS Softech M365 Tenant to Tenant Migration Tool.
Conclusion
In this technical blog post, we explored several methods to migrate emails from Office 365 Tenant to Tenant. The manual method requires Microsoft 365 Admin Center, Exchange Admin Center, and PowerShell. But it has several limitations. That’s why it’s best to use the professional tool. It supports bulk migration of Mailbox, SharePoint, or OneDrive. You can download the trial version of this tool to migrate 500 emails, 100 contacts & calendar per User.
Frequently Asked Questions
Ans. You can migrate emails using Microsoft’s native Cross-Tenant Mailbox Migration or a professional migration tool. The native method requires Microsoft 365 Admin Center, Exchange Admin Center, and PowerShell, while a professional tool simplifies the process with a graphical interface and bulk migration support.
Ans. Yes. You can migrate only Exchange Online mailboxes if you don’t need to move SharePoint sites or OneDrive data. DRS Softech tool allows you to select only the workload you want to migrate.
Ans. Yes. A reliable migration solution preserves the original mailbox folder hierarchy, including Inbox, Sent Items, Drafts, custom folders, and subfolders, so users can access their data as before.
Ans. Yes. Large mailboxes can be migrated successfully with proper planning and sufficient Microsoft 365 resources. The migration duration depends on mailbox size, internet bandwidth, and Microsoft service throttling.
Ans. Yes. Microsoft recommends using Modern Authentication (OAuth 2.0) for secure access during tenant-to-tenant migration. It provides better security than legacy authentication methods.
Ans. Yes. Administrators can perform batch migration of multiple mailboxes at the same time. This significantly reduces the overall migration time for large organizations.
Ans. Yes. Mailbox data is transferred securely using Microsoft’s authentication protocols and encrypted communication channels. A professional migration tool uses secure APIs to protect data during migration.
Ans. It depends on the mailbox type and licensing. Inactive mailboxes retained under Microsoft 365 compliance policies may require additional configuration before migration. Disabled user accounts should be reviewed and prepared before starting the migration.
Ans. No. Duplicate removal only identifies and removes duplicate items based on the selected criteria. The source mailbox remains unchanged unless you explicitly perform a deduplication operation on it.
Ans. Yes. Removing duplicate emails before migration reduces the amount of data being transferred, which can shorten migration time, lower storage usage, and improve overall migration efficiency.
Ans. Yes. Microsoft may temporarily throttle migration requests to protect service performance, especially during large migrations. Using incremental migration, scheduling migration batches during off-peak hours, and leveraging tools that handle throttling automatically can help minimize interruptions.
