21713: Messaging Service Use Case is Invalid

The Messaging Service use case you are trying to specify in the request is not a valid use case.

• The Messaging Service use case specified in the request is not a valid Messaging Service use case. Valid Messaging Service use cases include: discussion, marketing, notifications, poll, undeclared and verification.

• Verify that you are spelling the use case correctly in your request and that it is using all lowercase letters.