If your organization has a need to mass-create AD user accounts, watch this video to see how its done without the need for scripting or other unnecessary complexities.
Source: MSExchangeTransport Category: NDR Event ID 3020 Cause: A forward loop was detected by the categorizer. This is a common hosting configuration problem caused when someone uses the provisioning tool to create a contact in one organization unit and creates a user in a different organization user that share the same e-mail address. Solution: Verify that you do not have a user in organizational unit and a contact in a different organizational unit that have the same e-mail address. For more information, see Help and Support Center at