A default deployment of the add-in allows users to disable the add-in manually in Microsoft Outlook or other Office applications.

Admins can override this setting by enabling the relevant group policy setting. This setting will prevent users from manually disabling the add-in.

To prevent users from disabling the Outlook add-in, open the Group Policy Editor and check that the Office Administrative Templates are installed. These can be located in User Configuration Administrative Templates Microsoft Outlook [YEAR] Miscellaneous.

If they are not installed, the administrative templates for Microsoft are available at the below URL:

• Office 2016: https://www.microsoft.com/en-us/download/details.aspx?id=49030

Complete the following steps below to ensure that users cannot disable an Office add-in:

1. Ensure that the List of managed add-ins setting is set to Enabled.
2. Select Show... in the List of managed add-ins.
3. Write "Egress.Switch" and set the value to 1. This action will ensure the add-in cannot be disabled.

Alternatively, it's possible to deploy the registry key via GPO. The registry key type should be REG_SZ.