How to Enable Auto-Expanding Archiving in Microsoft 365?

Microsoft 365 offers auto-expanding archiving, a feature that automatically increases storage when an archive mailbox reaches its limit. This ensures that users never run out of space for their emails, making it an essential feature for organizations with heavy email usage.

Prerequisites to Enable Auto-Expanding Archiving in Microsoft 365

Before enabling Auto-Expanding Archiving, ensure that you meet the following requirements:

1. Licensing Requirements

Your Microsoft 365 plan must include auto-expanding archiving, which is available in:

  • Microsoft 365 E3 / E5
  • Office 365 E3 / E5
  • Microsoft 365 Compliance Plans

Note: Auto-expanding archiving is NOT available in Business Standard or Business Premium plans.

2. Admin Permissions

You must have one of the following roles in Microsoft 365:

Global Administrator, Exchange Online Administrator

3. Archive Mailbox Must Be Enabled

Before enabling Auto-Expanding Archive, the user must already have an archive mailbox enabled. If not check how to enable Archive mailbox in Office 365.

4. PowerShell Access

Install and import the Exchange Online module (if not already installed):

Install-Module ExchangeOnlineManagement Import-Module ExchangeOnlineManagement Connect-ExchangeOnline -UserPrincipalName youradmin@yourdomain.com

Steps to Enable Auto-Expanding Archiving in Microsoft 365

You can enable Auto-Expanding Archiving for a single user or for the entire organization using PowerShell.

For a Single User:

Step 1: Run PowerShell

Open PowerShell as an administrator.

Note: Make sure you Launch Windows PowerShell as "Run as Administator"

Step 2: Connect to Exchange Online PowerShell

Now Execute the below command to connect to Exchange Online:

Connect-ExchangeOnline -UserPrincipalName youradmin@yourdomain.com

Step 3: Enable Auto-Expanding Archive

Execute the below command to enable Auto-Expanding Archive

Enable-Mailbox -Identity user@yourdomain.com -AutoExpandingArchive

Step 4: Verify Auto-Expanding Archiving

Execute the below command to Verify Auto-Expanding Archiving

Get-Mailbox -Identity user@yourdomain.com | FL AutoExpandingArchiveEnabled

If it returns True, auto-expanding archiving is successfully enabled.

For the Entire Organization

To enable auto-expanding archiving for all mailboxes in your organization:

Step 1: Connect to Exchange Online PowerShell

Connect-ExchangeOnline -UserPrincipalName youradmin@yourdomain.com

Step 2: Enable Auto-Expanding Archive Organization-Wide

Set-OrganizationConfig -AutoExpandingArchive $true

Step 3: Enable Auto-Expanding Archive for All Users

Get-Mailbox -Filter {ArchiveStatus -eq "Active"} | ForEach-Object {Enable-Mailbox -Identity $_.PrimarySmtpAddress -AutoExpandingArchive}

Step 4: Verify Organization-Wide Auto-Expanding Archiving

Get-OrganizationConfig | Select AutoExpandingArchiveEnabled

If it returns True, auto-expanding archiving is successfully enabled.

Important Note

  • It can take up to 30 days until additional storage space (another 100 GB) is provisioned for an archive mailbox in Exchange Online.
  • If you use the Enable-Mailbox cmdlet to enable the auto-expanding archiving feature for a specific user, the storage quota for this user's archive mailbox is automatically increased by 10 GB (from 100 GB to 110 GB).
  • If you have already enabled auto-expanding archiving by running Set-OrganizationConfig, you can still use Enable-Mailbox to get the additional storage space for a specific user. The additional 10 GB is added instantly to the mailbox quota, which can prove useful when migrating archive mailboxes that are larger than 100 GB but not larger than 110 GB.