Install and Connect to the Exchange Online PowerShell Module

1. Install the Exchange Online Management Module:
   

1. Open PowerShell as an administrator.
   
2. Install the Exchange Online Management module by running the following command:
   
1. #Install-Module -Name ExchangeOnlineManagement
   
3. If prompted to install the NuGet provider, confirm by typing Y and pressing Enter.
   
4. If prompted to install the module from the PSGallery, confirm by typing Y and pressing Enter.
   

2. Import the Exchange Online Management Modul:
   

1. Import the module into your session:
   
1. #Import-Module ExchangeOnlineManagement
   

3. Connect to Exchange Online:
   

1. Connect to Exchange Online with the following command:
   
2. Use the Connect-ExchangeOnline command to connect to Exchange Online. Replace admin@yourdomain.com with the actual admin email address:
   
1. #Connect-ExchangeOnline -UserPrincipalName user@domain.com -ShowProgress $true
   
3.  A sign-in window will appear. Enter the Office 365 admin credentials.
   

4. Enable Auto-Expanding Archiving:
   

1. Once connected, run the command to enable auto-expanding archiving:
   
2. Replace user@domain.com with Auto expand username@domain.com
   
1. #Enable-Mailbox -Identity "user@domain.com" -AutoExpandingArchive
   

Verify the Archive Auto Expanding status

1. Check Archive Status via PowerShell
   

1. You can check the status of the auto-expanding archive by running a PowerShell command to get the mailbox details and specifically look for the AutoExpandingArchiveEnabled property.
   
1. #Get-Mailbox -Identity "user@domain.com" | Format-List AutoExpandingArchiveEnabled
   

2. Check Archive Status via Exchange Admin Center (EAC)
   

You can also verify the status through the Exchange Admin Center (EAC):

1. Login to EAC:
   

1. Go to the Exchange Admin Center (https://admin.exchange.microsoft.com/).
   
2. Login with your admin credentials.
   

2. Navigate to Recipients:
   

1. In the left pane, click on "Recipients."
   
2. Click on "Mailboxes."
   

3. Select the User Mailbox:
   

1. Find and select the mailbox for which you enabled auto-expanding archiving.
   

4. Check Archive Settings:
   

1. In the mailbox properties pane, check the "In-Place Archive" section to see if the auto-expanding archive is enabled.
   

5. Use PowerShell to Get Detailed Archive Information
   

1. For a more detailed view of the archive properties, you can use the Get-Mailbox cmdlet combined with Format-List to display all relevant archive properties.
   
1. #Get-Mailbox -Identity "user@domain.com" | Format-List *archive*
   
2. This will show detailed information about the mailbox's archive settings, including ArchiveStatus, ArchiveDatabase, ArchiveGuid, ArchiveName, ArchiveQuota, ArchiveWarningQuota, and AutoExpandingArchiveEnabled.
   

6. Verify Archive Size and Growth
   

1. To monitor the size and growth of the archive mailbox, you can use the Get-MailboxStatistics cmdlet. This can help you track the usage over time to see if the archive is expanding.
   
1. #Get-MailboxStatistics -Identity "user@domain.com" -Archive | Select DisplayName, TotalItemSize, ItemCount
   
2. This command will display the archive mailbox statistics, including the total size and the number of items in the archive.
   

Archive Status via Exchange Admin Center (EAC)