Managing mailbox storage is one of the most common challenges for Microsoft 365 administrators. As users continue to send and receive large volumes of emails, mailbox sizes quickly grow, leading to storage quota warnings, performance concerns, and compliance issues. That’s where In-Place Archive mailboxes in Microsoft Exchange Online become essential.
An archive mailbox provides users with additional mailbox storage that appears as a separate Online Archive folder in Outlook and Outlook on the web. Instead of deleting old emails, organizations can move them into the archive mailbox to support long-term retention, compliance requirements, and mailbox lifecycle management.
What Is an In-Place Archive Mailbox?
An In-Place Archive mailbox is a secondary mailbox associated with a user’s primary mailbox in Exchange Online. It is designed to store older or less frequently accessed emails while keeping them accessible to users. Once enabled, users will see an additional mailbox section called: Online Archive – User Name
Archive mailboxes help organizations free up space in primary mailboxes by storing older emails separately while still keeping them accessible to users. They also support compliance and long-term email retention, helping businesses preserve important communications without using PST files. By keeping primary mailboxes cleaner and more organized, archive mailboxes make mailbox management easier for both users and administrators.
Archive Mailbox vs Retention Policy
Many administrators confuse archive mailboxes with retention policies because both help manage emails in Exchange Online. However, they work differently.
An archive mailbox gives users extra storage space by creating a separate Online Archive folder for older emails. A retention policy, on the other hand, controls how long emails are kept and can automatically move or delete emails after a certain period.
Organizations often use both together. For example, a retention policy can automatically move old emails from the primary mailbox to the archive mailbox, helping keep mailboxes organized while meeting compliance and retention requirements.
How to Enable Archive Mailboxes in Exchange Online
To enable In-Place Archive (Online Archive) mailboxes in Exchange Online, use the modern Exchange admin center (EAC) or connect to Exchange Online PowerShell. Archiving provides users with extra storage space and helps manage mailbox size limits.
Method 1: Using the Exchange Admin Center (EAC)
You cannot change mailbox settings without the right permissions. Your account must be assigned one of these roles in Exchange Online: Global administrator or Exchange administrator.
- Sign in to the Exchange admin center.
- In the left navigation pane, go to Recipients > Mailboxes.
- Click on the user whose mailbox you want to enable for archiving.
- In the flyout details pane, click the Others tab.
- Under Mailbox archive, click Manage mailbox archive.
- Switch the Mailbox archive toggle to On and click Save.
While enabling archive mailboxes is technically simple, finding the correct setting in the Exchange admin center can take longer than expected. Microsoft places the archive option inside the “Others” tab together with unrelated settings, which may confuse administrators who are new to Exchange Online management.
Even though Microsoft provides built-in tools for mailbox archiving, the process is not always simple. Archive settings are spread across different admin portals, and some tasks require PowerShell. Managing archives for many users and checking archive status can also take extra time, especially in larger organizations.
Method 2: Using Exchange Online PowerShell
If you are managing bulk users or prefer CLI, open PowerShell as an administrator and run the following after connecting to Exchange Online PowerShell.
Enable an Online Archive for a specific mailbox:
Enable-Mailbox -Identity 'user@contoso.com' -ArchiveEnable archive mailboxes in bulk for users who do not already have one:
Get-Mailbox -ResultSize Unlimited -Filter {ArchiveStatus -eq 'None'} | `
Enable-Mailbox -ArchiveCheck archive mailbox status and quota details:
Get-Mailbox -Identity 'user@contoso.com' | `
Select ArchiveStatus, ArchiveQuota, ArchiveNameView archive mailbox size and item statistics:
Get-MailboxStatistics -Identity 'user@contoso.com' -Archive | `
Select DisplayName, TotalItemSize, ItemCountSimplify Archive Mailbox Management Without PowerShell: EasyEntra
For administrators who want to manage archive mailboxes without navigating the admin portal or writing PowerShell scripts, EasyEntra provides a streamlined alternative. Everything is handled directly from the user’s properties panel.
Enabling Archive in EasyEntra
In EasyEntra, mailbox archiving is managed through the User Properties Panel. Here’s how to get there:
- Navigate to the Users section in EasyEntra and click on the user you want to configure. This opens their full properties panel.
- Inside the User Properties panel, click on the Mailbox tab to view mailbox-related settings.
- Within the Mailbox Storage section, click the Mailbox Archive option. A panel will appear with an Enable archive checkbox.
- Select the Enable archive checkbox and confirm. The change is applied immediately, no PowerShell, no multiple portals, no refresh required.
EasyEntra communicates directly with Exchange Online on your behalf. The UI reflects the current state in real time, and there is no need to refresh or wait for the portal to sync.
