How to Migrate Email Between Two Microsoft 365 Tenants

Written By
Simran Bhatia
Approved By
Sonika Rawat
Updated on
June 2nd, 2026
Read Time
10 minutes

“I require detailed steps to migrate emails of around 40 GB data each with 7 accounts from one Microsoft Tenant to another tenant. Kindly suggest a reliable, secure, and scalable solution for this migration with no data loss. Thanks.”

-R Singh, Microsoft Q&A

Mergers, acquisitions, and divestitures are some situations that highly demand mailbox consolidation or migration for continued business operations. As an admin, it is your responsibility to ensure that email migration from one tenant to another happens securely. So, no matter if you have moved mailboxes before, a single wrong step can result in downtime of mission-critical systems and bring security gaps. Therefore, read this technical guide to find feasible solutions, including a SysInfo Microsoft 365 Tenant to Tenant Migration Tool for keeping your migrations secure and simplified without risks.

Windows
Mac

Download Buy Now

Quick Answer: How to Migrate Email Between Two Microsoft 365 Tenants?

Use the native Microsoft cross-tenant migration method or an efficient Microsoft 365 Migration Tool to move domain between Office 365 tenants. It is a fact that email migration isn’t just a copy/paste task and doesn’t fit in all cases. Your chosen solution reflects how your enterprise functions and deals with the critical data.

Table of Contents

Prerequisites to Migrate Emails from One Tenant to Another

Before you proceed with the migration process, especially manually, you must ensure that these requirements are fulfilled:

Admin access for both the source and target tenants
Licences assigned appropriately for M365 tenants
Verification of target tenant domains (if users retain the same email address)
Proper identity configuration and good network bandwidth
At least one mail-enabled security group must exist in the source tenant

No-Cost Email Migration From One Tenant to Another

The manual method comprises a built-in cross-tenant migration solution using Exchange Online PowerShell and Microsoft Admin Center. The steps to follow are divided into different sections for a clearer understanding:

1) Prepare the Target Tenant

This is the first step for native migration, which requires your tenant admin access and credentials.

Sign in to Microsoft Entra Admin Center using target tenant admin credentials.
Then, within Manage Microsoft Entra ID, click View and from the navigation pane, click App Registrations.
Choose New Registration and give it a name. Also, select the supported account type (Any Microsoft Entra directory – Multi-tenant).
You can optionally add the redirection URL as https://office.com. Hit Register.
Further, move back to Home, and under Owned applications, find your App.
Next, from Essentials, copy your Application (client) ID. Afterward, move to API Permissions.
User.Read permissions are already assigned. To add new, click Add Permission and locate Office 365 Exchange Online.
Select it and click Application Permissions. From the displayed ones, expand Mailbox and choose Mailbox.Migration.
Click Add Permission and later go to Certificates & secrets from the navigation pane.
Within Client Secrets, click +New Client Secret and enter a description and configure expiration settings.
Later, from API Permissions, choose Grant Admin Consent for your Tenant and click Accept in the open window.
Refresh to confirm the acceptance and provide the given consent URL to your source tenant admin.

https://login.microsoftonline.com/<source-tenant-onmicrosoft>.com/adminconsent?client_id=<YourCreatedAppID>&redirect_uri=https://office.com

2) Configure Target Tenant Endpoint and Relationship

Follow the second phase for manual email migration from one tenant to another in the target tenant.

First, connect to the Exchange Online PowerShell in the target tenant.
Then, prepare a new migration endpoint with the given command:

$AppId = “<Your-Created-App-ID>”

$name = “[Name-of-Migration-Endpoint]”

$Secret = “<Your-Client-Secret-From-Earlier>”

$RemoteTenant = “<source-tenant>.onmicrosoft.com”

$Credential = New-Object -TypeName System.Management.Automation.PSCredential -ArgumentList $AppId, (ConvertTo-SecureString -String $secret -AsPlainText -Force)

New-MigrationEndpoint -RemoteServer outlook.office.com -RemoteTenant $remote -Credentials $Credential -ExchangeRemoteMove:$true -Name $name -ApplicationId $AppId

After that, create a new organizational relationship or edit the existing one to the source tenant with these commands:

$sourceTenantId = “[Your Source Tenant ID]”

$orgrelname = “[Name of New Org. Relationship]”

$orgrels = Get-OrganizationRelationship

$existingOrgRel = $orgrels | ?{$_.DomainNames -like $sourceTenantId}

If ($null -ne $existingOrgRel)

{

Set-OrganizationRelationship $existingOrgRel.Name -Enabled:$true -MailboxMoveEnabled:$true -MailboxMoveCapability Inbound

}

If ($null -eq $existingOrgRel)

{

New-OrganizationRelationship $orgrelname -Enabled:$true -MailboxMoveEnabled:$true -MailboxMoveCapability Inbound -DomainNames $sourceTenantId

}

Next, prepare the source tenant by accepting the application and configuring relationships.
Use the consent URL from above and accept the application from the pop-up.
Furthermore, connect to Exchange Online PowerShell on the source tenant.
Again, create a new org. Relationship or edit an existing one to the target tenant with the command:

$targetTenantId = “[Target-Tenant-ID]”

$appId = “[Application ID of Mailbox Consented]”

$scope = “[Mail Enabled Security Group Name for Migration]”

$orgrelname = “[New Org. Relationship Name]”

$dehydrated = Get-OrganizationConfig | select isdehydrated

if ($dehydrated.isdehydrated -eq $true) { Enable-OrganizationCustomization }

if (!(New-DistributionGroup -Type Security -Name $scope)) { Write-Host “Group already exists.” }

$orgrels = Get-OrganizationRelationship

$existingOrgRel = $orgrels | ?{$_.DomainNames -like $targetTenantId}

if ($null -ne $existingOrgRel)

{

Set-OrganizationRelationship $existingOrgRel.Name -Enabled:$true -MailboxMoveEnabled:$true -MailboxMoveCapability RemoteOutbound -OAuthApplicationId $appId -MailboxMovePublishedScopes $scope

}

if ($null -eq $existingOrgRel)

{

New-OrganizationRelationship $orgrelname -Enabled:$true -MailboxMoveEnabled:$true -MailboxMoveCapability RemoteOutbound -DomainNames $targetTenantId -OAuthApplicationId $appId -MailboxMovePublishedScopes $scope

}

3) Prepare Target User Objects

This is the last phase for manual mailbox migration from one MS Tenant to another.

Initially, ensure that each user in the target tenant exists at MailUser with a matching ExchangeGUID of the source tenant.
Try finding the objects that were previously mailboxes with the given command:

Get-User <useridentity> | select Name, *recipient* | Format-Table -AutoSize

Further, clear the soft-deleted mailbox with the PowerShell cmdlet:

Set-User <useridentity> -PermanentlyClearPreviousMailboxInfo

Afterward, verify your email migration from one tenant to another configuration with:

Test-MigrationServerAvailability -EndPoint “[Migration Endpoint Name]” -TestMailbox “[Target Tenant Primary SMTP of MailUser Object]”

Next, prepare the migration batches with the command:

New-MigrationBatch -Name “Name of Batch” `

-SourceEndpoint “CrossTenantEndpoint” `

-CSVData ([System.IO.File]::ReadAllBytes(“C:\migration.csv”)) `

-TargetDeliveryDomain “<target-domain>.onmicrosoft.com” `

-AutoComplete $false

Later, start the migration batch and monitor its progress using the command:

Get-MigrationBatch

Get-MigrationUser

Get-MailUser -Identity <Migrate Mail User> | Enable-RemoteMailbox //to have users remote on-premises

At last, remove the endpoints and organizational relationships using the command:

Remove-Migration Endpoint

Remove-Organizational Relationship

That’s it. We have finally completed the manual process to migrate email between two Microsoft 365 tenants. However, this method is too complex, hectic, and unsuitable for users from a non-technical background.

The method requires a very high level of technical expertise and proficiency with admin credentials to perform the migration successfully. A single mistake or wrong command can hamper the data within the source tenant mailbox directly, resulting in loss or corruption. So, what’s next? How can you migrate OneDrive to another tenant alongwith email mailboxes and SharePoint securely? Find out below.

Partner-Based Email Migration from One Tenant to Another

While the manual method is lengthy and complex, the SysInfo Microsoft 365 Tenant to Tenant Migration Software makes migration simple. No PowerShell and no Exchange Center needed, just your admin credentials, and you are good to go. From adding a source tenant to the mailbox mapping and transferring data into the target tenant, this software helps automate migration with advanced features, an intuitive interface, real-time progress tracking, and more.

Quick Guide to Migrate Emails from One Tenant to Another

Run the SysInfo Office 365 Migration Tool and click on Copy Mailboxes.
Then, pick Modern Authentication and select the source tenant. Authenticate.
Further, choose the source tenant user IDs to migrate data from and click Continue.
Afterward, choose the Modern/Client ID Authentication, Use Saved Credentials, or Add New, and authenticate the target tenant.
Later, verify the selected source mailboxes for migration and tap Continue to Mailbox Mapping.
Now, map the target tenant accounts to the source tenants and check the status.
Finally, use the filters, select the destination, and click Start Migration to initiate the export.
You can check the migration report from All Reports and confirm the progress and completion status.

Why SysInfo for Mailbox Migration From One MS Tenant to Another?

SysInfo supports handling hundreds or thousands of source tenant mailboxes in a single go without risks. It has several authoritative and secure features and filters, and can even migrate SharePoint site to another tenant alongwith mailboxes and OneDrive with 100% accuracy.

Core Capabilities Offered:

Graph API usage for Modern OAuth2.0 authentication and login via Client ID and Secret.
Delta migration support with the Skip Previously Migrated feature to eliminate redundancy.
Deduplicate email mailboxes, SharePoint, and OneDrive pre-migration and during the migration.
Ability to perform manual and automated mapping for one-to-many, many-to-one, one-to-one, and many-to-many source and tenant accounts.
Unified visibility of your data across tenants is manageable from a central dashboard.
Live progress tracking and real-time monitoring of the entire migration process with no hassle.
For more assistance on the core functionalities, check out the Features of the specialized tool.

Real Query Resolved Right!

In May 2026, we received a few queries from our trusted client (Geordie McRae) stating:

“I want to keep the migrated email box up to date. How do I do this so only new emails are copied and not duplicates?”

“Getting Migration failed error when using OneDrive copy.”

We helped him resolve his queries with complete technical assistance and a stepwise guide on authenticating OneDrive and using the deduplication and incremental migration feature for a duplicate-free mailbox copy. This ensured a smooth mailbox migration from one MS Tenant to another.

Wrapping Up

Email migration from one tenant to another in the correct way is only possible when you use the right strategy and reliable software solutions. Whether you go for the Microsoft native cross-tenant migration solution or use the robust SysInfo Office 365 Tenant to Tenant Migration Tool. The latter will ensure zero data loss migration with forensic precision and no disruption to continued business operations. For any queries, contact the migration specialists and ensure a no-downtime tenant-to-tenant migration.

Frequently Asked Questions

Q 1. Is it possible to migrate emails from one Microsoft 365 tenant to another without data loss?

Ans. Yes, you can migrate emails between Microsoft 365 tenants without data loss using the SysInfo Microsoft 365 Migrator Tool. It ensures guaranteed data fidelity without affecting or deleting the original data in source tenant IDs.

Q 2. What data can be migrated during a Microsoft 365 tenant-to-tenant email migration?

Ans. You can migrate all kinds of data during a Microsoft 365 migration from one tenant account to another. It includes all mailbox items like emails, folders, attachments, calendars, contacts, tasks, and email metadata.

Q 3. Can I migrate multiple Microsoft 365 mailboxes simultaneously?

Ans. Yes, migrating multiple Microsoft 365 email mailboxes simultaneously is possible with both the native method and the SysInfo Microsoft 365 Tenant Migration Tool. It supports migrating hundreds of mailboxes in parallel with no difficulties. All you need to ensure is to have the technical capability for manual migration.

Q 4. Will email metadata remain unchanged after migration?

Ans. Yes, the professional SysInfo Tenant Migration Tool keeps the email metadata preserved, including all message headers, timestamps, and read/unread status. It makes sure that nothing is lost during the process.

Q 5. How do I migrate emails from one tenant to another without changing email addresses?

Ans. To migrate emails between two tenants without changing email addresses, you may add the domain as an accepted domain in the target tenant. Later, perform the domain cutover by updating the MX records after migration in the native process.

Q 6. How do I avoid duplicate emails during tenant migration?

Ans. Use the incremental syncs or the de-duplication and Remove Duplicate feature from the SysInfo Tenant to Tenant Migration Tool. It will identify similar emails based on To, From, Subject, CC, and Body, and remove them by the same.

Q 7. Can enterprises perform email migration between tenants without disrupting users?

Ans. Yes, running email migration during off-peak hours or using the dependable Microsoft 365 Tenant to Tenant Migration Tool by SysInfo ensures no user is disrupted during migration in enterprises.

Rate this post

About The Author:

Simran Bhatia

Simran Bhatia is a technical content writer engaged in writing clear, concise, and SEO-optimized content. With a background in computer science and a passion for writing, I thrive to deliver complex technical content in simple layman terms.

How to Migrate Email Between Two Microsoft 365 Tenants

Prerequisites to Migrate Emails from One Tenant to Another