There’s no built-in feature at this time to enable litigation hold for all mailboxes in Exchange Online, but some organisations have this as a requirement. Here’s a script that can be run ad-hoc to enable litigation hold for all mailboxes. When prompted, enter your Exchange Online credentials.
# Connect to Exchange Online
$exo = New-PSSession -ConfigurationName Microsoft.Exchange `
-ConnectionUri https://ps.outlook.com/powershell-liveid `
-Authentication Basic `
-AllowRedirection `
-Credential $(Get-credential)
Import-PSSession $exo
# Get all mailboxes that do not have litigation hold enabled
$mailboxes = Get-Mailbox -ResultSize Unlimited -Filter {RecipientTypeDetails -eq “UserMailbox”} |
Where {$_.LitigationHoldEnabled -ne $true}
# Enable litigation hold
$mailboxes | Set-Mailbox -LitigationHoldEnabled $true
Remove-PSSession $exo
