Email Migration

How to Consolidate Multiple Microsoft 365 Mailboxes into One

WPS Editor Oct 8, 2026 869 views

Question details

The user needs a way to merge or consolidate data from multiple Microsoft 365 user mailboxes into a single primary mailbox.

How to Consolidate Multiple Microsoft 365 Mailboxes into One

Product: Microsoft 365
Device & OS: not provided
Scenario: Simplifying email management by combining multiple separate user accounts into one, avoiding the need to maintain several independent mailboxes.
Observed behavior: Microsoft 365 does not offer a native one-click merge feature for user mailboxes, requiring manual data migration via export/import or changing mailbox types.

Before you start

Ensure you have the Microsoft Outlook desktop client installed to perform data exports, and verify that you have global administrator access to the Microsoft 365 admin center if you need to modify mailbox permissions.

Solution 1Recommended

Export and Import Mailbox Data via PST Files

This is the most effective method for completely merging mailbox data (emails, contacts, and calendar items) into a single destination mailbox without retaining multiple active accounts.

Since Microsoft 365 does not natively merge accounts, exporting the data from the secondary accounts into a local PST file and then importing that file into the primary account is the standard workaround. This allows you to safely delete the old accounts afterward to save on licensing costs.

Configure the source mailbox in Outlook

Add the Microsoft 365 email account you want to deprecate to your Microsoft Outlook desktop client.

Export data to a PST file

In Outlook, navigate to File > Open & Export > Import/Export. Choose 'Export to a file', select 'Outlook Data File (.pst)', and ensure you include all subfolders to capture emails, contacts, and calendar events. Save the file to your computer.

Configure the destination mailbox

Add your primary Microsoft 365 mailbox (the one you want to keep) to the Outlook desktop client.

Import the PST file

Go back to File > Open & Export > Import/Export. Select 'Import from another program or file', choose 'Outlook Data File (.pst)', locate your saved file, and import the contents into the primary mailbox.

Transfer aliases and delete old account

If you need to keep receiving emails sent to the old address, log into the Microsoft 365 Admin Center, remove the old email address from the deprecated account, add it as an alias to your primary account, and then delete the old user account.

Export and Import Mailbox Data via PST Files

Data Preservation: Exporting to a PST file ensures that your folder structure, calendar appointments, and contact lists remain fully intact during the transfer.

Solution 2

Convert Secondary Accounts to Shared Mailboxes

Use this method if you want to keep the mailboxes separate but manage them all from a single login without paying for extra licenses.

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Frequently Asked Questions

Can I merge two Microsoft 365 mailboxes with a single click?

No, Microsoft 365 does not offer a native one-click merge feature. You must either export the data to a PST file and import it into the destination mailbox, or convert the secondary account into a shared mailbox.

Will exporting to a PST file keep my calendar and contacts?

Yes, when you export your mailbox to a PST file in Outlook, you can choose to include all subfolders. This ensures your calendar events, contacts, and tasks are preserved alongside your emails.

What happens to my email addresses when I delete the old account?

If you delete a Microsoft 365 user account, its associated email addresses stop receiving mail. To prevent this, remove the email address from the old account before deletion, and add it as a secondary 'alias' to your primary mailbox.

Migration & Recovery