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A mailbox is a make-or-break deal for many professionals during a busy day. A well-organized mailbox can start your workday on a productive note as it sets the tone for the entire day. But heavy traffic of incoming messages often keeps the mailbox full. If you have an oversized mailbox, it will directly impact the functioning of Outlook. It pushes the application to become slower, and users often cannot send or receive emails. Hence, it is wise to adopt a regular practice to archive mails in Office 365.

To avoid such issues, Microsoft introduced the Online Archive mailbox, where you can manually or automatically archive all the critical older email messages in a mailbox other than the primary one. This facility has proved fruitful for all organizations and professionals, and you should enable it without further delay.

What is Outlook Online Archive?

Online Archive in Microsoft 365 refers to a process where a separate and specialized mailbox is created to free up disk space and clean the primary mailbox. This mailbox is different from your Primary Exchange Mailbox. Users can manually or automatically move their older emails to the archive mailbox while maintaining the exact structure of the data. It is also referred to as an In-Place Archive or Outlook Archive.

What is the difference between Outlook Online Archive and the Archive folder?

Some individuals often interchangeably use the terms- Online Archive and Archive folder. They do have the same function but still are different from each other. To put an end to all the confusion, here is the difference between the two-

  • Archive folder- The Online Archive folder is one of the default folders in your Outlook mailbox. It is similar to Inbox, Sent Items, Drafts, Deleted Items, etc. Users prefer to move their messages to this folder to clear up some space in their Inbox and keep it organized. It doesn’t reduce the primary mailbox’s size since it is a separate folder.
  • Online Archive- The Online Archive is a separate mailbox to keep all the archived information. It is designed to free up space from the user’s primary mailbox. It is not a default feature and has to be enabled by the admin. You can manually move emails or set up retention policies to do the task.
How much space does the Outlook Online Archive mailbox offer?

The Online Archive facility is included in most Microsoft 365 plans. However, the archiving space is either 50GB or 1.5TB, depending on your plan, and it is distributed as follows-

Archiving space Plans
50 GB Microsoft 365 Business Basic
Microsoft 365 Business Standard
Office 365 E1
1.5 TB Microsoft Business Premium
Office 365 E3
Office 365 E5
Microsoft 365 E3
Microsoft E5

It is essential to know that 1.5TB is not the initial size. Once your archive reaches 90% of its capacity, you can expand it by 100GB until it reaches the 1.5TB limit.

How to enable Outlook Online Archive?

The admin can enable the Outlook Online Archive using the Exchange Admin Center, PowerShell, or Purview Compliance Portal based on each user or organization. The detailed process is as follows-

  1. Using the Exchange admin center
    This method is suitable when you need to enable the archiving mailbox on a user basis.

    1. Open the Exchange Admin Center.
    2. Click on Recipients and select Mailboxes.Exchange Admin Center
    3. Click on the user and move to the other tab. Click on Manage mailbox Archive.Manage mailbox Archive
    4. Turn on the Mailbox archive. It takes some time to create the archive mailbox.Mailbox archive
  2. Using PowerShell-
    This approach is suitable for quickly creating the archive mailbox for multiple users in the entire organization.

    1. Open PowerShell and connect it to Exchange Online.
    2. Run the following command to turn on the Online archive for a single user-
      Enable-Mailbox -Identity <username> -Archive
    3. Run the following command to turn on the Online archive mailbox for multiple users-
      Get-Mailbox -Filter {ArchiveGuid -Eq “00000000-0000-0000-0000-000000000000” -AND RecipientTypeDetails -Eq “UserMailbox”} | Enable-Mailbox -Archive
  3. Using Microsoft Purview Compliance Portal-
    Before moving forward to the steps, you need to have the necessary permissions to utilize this approach.

    1. Open the Microsoft Purview Compliance portal using the following link-
    2. From the left panel, select Data lifecycle management and click on Microsoft 365.Data lifecycle management
    3. Under the Archive tab, select the user and click on Enable archive.Enable archive

Once the archive mailbox has been enabled using any of the methods mentioned above, it will be visible just below their primary mailbox. At times, users assume that their Exchange Archive mailbox is not displaying in Outlook; in that case, restart Outlook and check again.

How to disable Outlook Online Archive?

The Online Archive can easily be disabled using the same approaches. Once you disable the user’s archive mailbox, you can connect it again within 30 days. It will restore the original contents of the archive mailbox. However, reconnecting it after 30 days creates a new archive mailbox while permanently deleting the original content. The detailed steps of each are as follows-

  1. Using Exchange Admin Center-
    1. Select the user. Move to the Other tab.
    2. Click on Manage mailbox archive and turn off the Mailbox archive option.
  2. Using PowerShell-
    1. Command to disable Online Archive for a single user-
      Disable-Mailbox -Identity <username> -Archive
    2. Command to disable Online Archive for multiple users-
      Get-Mailbox -Filter {ArchiveGuid -Ne “00000000-0000-0000-0000-000000000000” -AND RecipientTypeDetails -Eq “UserMailbox”} | Disable-Mailbox -Archive
  3. Using Microsoft Purview Compliance Portal-
    1. In Data lifecycle management, open the Archive tab.
    2. Click on the user and select the Disable archive option present above.Disable archive


An Online Archive mailbox enables users to store all their older emails in a different mailbox with the original structure. It is helpful to maintain a neat and organized primary mailbox. Users often mistake this for the Archive folder feature, but the two have some stark differences. It can be enabled and disabled easily using the Exchange Admin Center, Microsoft Purview Compliance Portal, or PowerShell. You can add a double layer of protection to all your essential emails by taking a backup. You can make the most of the Kernel Office 365 Backup, a professional utility designed to backup the entire mailbox data and save it in a secure file format. The tool can be easily operated by expert and novice users.