# Unset OWAMailboxPolicy

## Introduction

It is no longer necessary to manually set [the `OWAMailboxPolicy`](https://learn.microsoft.com/en-us/powershell/module/exchange/set-owamailboxpolicy?view=exchange-ps) using PowerShell commands. This policy is now part of the default Outlook Web Access (OWA) functionality. If you have manually configured this policy for your users in the past, you must disable it to avoid unexpected behavior when users send emails from Outlook Web Access (OWA).

### Disable OWAMailboxPolicy

To disable OWAMailboxPolicy:

1. Connect to Exchange via PowerShell

```powershell
   Import-Module ExchangeOnlineManagement
   Connect-ExchangeOnline -UserPrincipalName admin@domain.com
   ```

2. Check the available OwaMailboxPolicies and their value for `OnSendAddinsEnabled`. Ensure that the default value is `FALSE`:
   `Get-OwaMailboxPolicy | fl name, onsendaddinsenabled`

3. Update the OwaMailboxPolicy for all users:
   `Get-User -Filter {RecipientTypeDetails -eq 'UserMailbox'} -ResultSize Unlimited | Set-CASMailbox -OwaMailboxPolicy OWAMailboxPolicy-Default`

4. Close the connection to Exchange:
   `Disconnect-ExchangeOnline`

5. Disable or delete the task that assigns the OwaMailboxPolicy to new users:
   1. Open the **Windows Task Scheduler**.
   2. Locate the task that enables the OwaMailboxPolicy.
   3. Disable or delete the task.

Updated on 2026-06-18