If the mailbox from which you want to remove the message is placed on In-Place Hold or Litigation Hold or has single item recovery enabled, Microsoft 365 preserves the mailbox data until the hold is removed or single item recovery is disabled.
In this case, you need to perform more detailed steps to recall the message from the Recoverable Items folder.
In-Place Hold
- Navigate to the Exchange Admin Center and log in using your administrator credentials
- Select compliance management from the menù on the left
- Check that there are no configurations under in-place eDiscovery & Hold
For further information visit: https://docs.microsoft.com/en-us/exchange/policy-and-compliance/holds/in-place-holds
Litigation Hold
- Navigate to the Exchange Admin Center and log in using your administrator credentials
- Select recipients from the menù on the left and then mailboxes
- In the list of user mailboxes, click the mailbox that you want to verify, and then click Edit
- On the mailbox properties page, click Mailbox features.
- Verify that the Litigation hold is Disabled
For further information visit: https://docs.microsoft.com/en-us/exchange/policy-and-compliance/holds/litigation-holds
Single Item Recovery
- Connect to Exchange Online via PowerShell
- Verify that the user has Single Item Recovery enabled
Get-Mailbox <Name> | Format-List SingleItemRecoveryEnabled - If the Single Item Recovery is enabled, disable it with:
Set-Mailbox -Identity <Name> -SingleItemRecoveryEnabled $false
For further information visit: https://docs.microsoft.com/en-us/exchange/policy-and-compliance/recoverable-items-folder/recoverable-items-folder