How Do I Migrate Emails Between Office 365 Accounts?

In today’s cloud-driven business world, email remains the backbone of professional communication. Many organizations using Microsoft 365 (formerly Office 365) eventually face the need to migrate emails between Office 365 accounts—whether due to internal restructuring, mergers and acquisitions, employee offboarding, or tenant-to-tenant migrations.

While Microsoft 365 offers a powerful suite of collaboration tools, migrating mailboxes between two Microsoft 365 accounts (either within the same tenant or across tenants) is not as simple as copying and pasting. It requires careful planning, the right tools, and a clear understanding of the technical processes involved to ensure zero data loss and minimal disruption.

In this article, we'll explain how email migration between Office 365 accounts works, the common use cases, best practices, and key limitations. We'll also answer frequently searched questions to help you navigate your migration journey confidently.

Why Migrate Emails Between Office 365 Accounts?

There are several real-world scenarios where businesses or IT teams need to migrate mailboxes between Microsoft 365 accounts:

Mergers and Acquisitions: Moving users from one company’s Microsoft 365 tenant to another
Department Restructuring: Shifting mailboxes to a different department or team domain
User Offboarding or Role Change: Consolidating or archiving emails of a former employee
Domain Name Changes: Migrating to a new domain under the same or different Microsoft 365 tenant
Compliance and Storage Optimization: Organizing data to meet retention or governance policies

Each of these scenarios can require different methods depending on whether the migration is happening within the same tenant or across different Microsoft 365 tenants.

Methods to Migrate Emails Between Office 365 Accounts

🔁 1. Manual Export and Import (for Small-scale Needs)

This method involves using Microsoft Outlook to export mail from one account as a .PST file, and then importing it into another account. It’s useful for individual users or small teams.

Steps:

Add both Office 365 accounts to Outlook
Export emails from the source account as a .PST file
Import the .PST file into the destination mailbox

Limitations:

Time-consuming
Doesn’t preserve shared mailbox or calendar data
Not suitable for large organizations or automation

☁️ 2. PowerShell and Exchange Online Admin Tools

For migrations within the same tenant, PowerShell scripts or Microsoft’s admin center tools (such as mailbox delegation or content copying) can be used to transfer emails between users.

Use cases:

Migrating a mailbox from one user to another within the same organization
Copying mailbox contents while preserving permissions

Pros:

Can automate part of the process
Retains message metadata

Cons:

Requires scripting experience
Limited for tenant-to-tenant migrations

🔄 3. Third-party Migration Tools

When migrating between different Microsoft 365 tenants, such as during mergers or domain transfers, third-party solutions like BitTitan MigrationWiz, Quest On Demand Migration, or AvePoint are often used.

These tools offer:

Bulk email migration with metadata and folder structure intact
Minimal downtime
Support for calendar, contacts, OneDrive, and Teams data
End-user email forwarding and coexistence

When to use:

Large-scale migrations
Cross-tenant migrations
Complex compliance or audit requirements

🔐 4. Mailbox to Shared Mailbox Conversion (Temporary Access)

Sometimes, instead of full migration, IT admins convert a user mailbox into a shared mailbox and grant access to another account. This is a quick solution during transitions.

Important: Shared mailboxes in Microsoft 365 do not require a license (unless over 50 GB), making this method cost-effective.

Best Practices for Migrating Emails Between Office 365 Accounts

Plan ahead: Define what needs to be moved—just emails or also calendar, contacts, and tasks.
Backup everything: Before migration, create full backups to avoid accidental data loss.
Inform users: Send clear communication about changes, expected downtime, and login credentials.
Check licenses: Ensure the destination account has appropriate Microsoft 365 licensing.
Test migration: Always run a pilot with a few accounts before full-scale rollout.
Update DNS if needed: Especially for tenant-to-tenant migrations involving new domains.

FAQs

❓1. Can I transfer emails from one Office 365 account to another?

Yes, you can transfer emails between Office 365 accounts using several methods. For small-scale migrations, exporting and importing via Outlook works. For organizational or tenant-to-tenant transfers, third-party tools or PowerShell scripting are often used to maintain structure and avoid downtime.

❓2. What is the best way to migrate Office 365 emails between tenants?

The most efficient and secure method for migrating Office 365 emails between tenants is by using third-party migration tools like BitTitan, Quest, or AvePoint. These tools support full mailbox, calendar, and OneDrive migration while preserving permissions, minimizing downtime, and maintaining compliance.

Final Thoughts

Migrating emails between Office 365 accounts is a task that requires more than just technical knowledge—it demands careful strategy, planning, and execution. Whether you're handling a simple role-based transition or a full-scale tenant-to-tenant migration, understanding the available tools and methods will help ensure success.

To avoid business disruption and ensure data integrity, it's best to consult with Microsoft 365 migration experts who can guide you through the right solution for your specific use case.