A non-delivery report with a status code of number was generated for recipient recipient (Message-ID message id).
Event Information
According to Microsoft: Cause: This Error event is logged when a non-delivery report (NDR) is generated because of a detected message loop. This event can also be logged if a contact object exists in one organizational unit (OU) that has the same e-mail address as a user in another OU. User Action : Verify that you do not have a user in one OU and a contact in another OU that have the same e-mail address.
