You can reset/remove the permissions that the ndMail application has been granted to the Exchange service.
To reset granted permissions:
- Go to the Azure portal and sign into a Microsoft account as a user with administrative access (it can be the same user that granted access to the Exchange service)
- Select Azure Active Directory > Enterprise applications.
- Select the entry for the ndMail application.
- In the Manage section on the left, select Properties.
- Select Delete at the top of this page.
- The ndMail application will no longer have access to the customer’s Exchange service
- If you repeat the steps to authorize the ndMail application, the Permissions dialog box will again appear when you authenticate through Microsoft.