How do I view the new mailbox editor in the .NET client?

Environment:

Email, Mailboxes, Office365, 20C and above

Process:

There is an extra step for viewing the OAuth enabled mailboxes editor in the .NET client after it has been enabled in a navigation set. In the Browser UI (BUI) client the new mailbox editor is the only one available.

You must create and enable a custom configuration to view the new editor in .NET.

1. From the Service Console, click Configuration on the navigation pane.
2. Expand Site Configuration, and then double-click Configuration Settings.
   The Search window opens.
3. Click Search.
4. Click New and select Yes/No on the ribbon.
   A new configuration setting opens on the content pane of the Configuration Settings editor. By default, the custom configuration setting name starts with CUSTOM_CFG_ and is automatically assigned to a Custom folder in the folder hierarchy.
5. To provide the setting to enable the new mailbox editor, enter CUSTOM_CFG_BUI_MB_ENABLED in the Key field.
   1. Click the Type drop-down list and select Site. Site classifies the custom configuration setting as whole site specific.
   2. Click the Required drop-down list and select whether the custom configuration setting is required. No is selected by default.
   3. Custom is the default folder. Leave this setting as it is.
   4. Enter a value in the Default field. We recommend No to match previous functionality.
   5. Click Save.

After you create the configuration you must set it to Yes (enabled) if you did not chose that as default.

Note that if you are logged into the .NET client you may need to log into the new mailbox editor which is technically using a BUI session.  This is expected and cannot be prevented.  If your account is using a profile that does not have access to BUI you will need to enable the profile permission used by your account, following Answer ID 10927: Needing login access to the Browser UI

Note that when searching for configurations you must choose Site under the Configuration Base drop down.

For information on enabling OAuth for Office365 mailboxes please refer to the documentation at https://documentation.custhelp.com/euf/assets/devdocs/buiadmin/topicrefs/t_configure_oauth_authentication_settings.html