Office 365 Install Exchange online and Force Archive with Powershell

Step 1: Install the Exchange Online Management Shell module

Install-Module ExchangeOnlineManagement

Step 2: Import the Exchange Online Management Shell module

Import-Module ExchangeOnlineManagement

Step 3: Connect to Exchange Online

Connect-ExchangeOnline

Step 4: Identify the Mailbox to Force Archive

Start-ManagedFolderAssistant -Identity <MailboxIdentity>

Step 6: Verify Archiving Status (Optional)

Get-MailboxFolderStatistics -Identity <MailboxIdentity>