No Workflow Message is Sent

A workflow DCN response is returned if the request is sent to a device that has no users mapped.

no workflow message is sent because no device is found 
to send the mail
Explanation: When a new messaging synchronization Workflow device user is created and registered from SAP Control Center, by default there are no users mapped to the device (Device Users > Devices > MBS user name > Users.... In this case, when sending a Workflow DCN request, the response is similar to:
{"id":"dcntest_test_001","success":false,"statusMessage":
"no workflow message is sent because no device is found to send the mail"
,"result":[{"id":"dcntest_test_data_1","success":true,"statusMessage":""}]} 

Workaround: Invoke any other SAP Mobile Platform application (for example, a client-initiated or server-initiated workflow application, or a native application), which maps an SAP Mobile Platform user to a messaging synchronization device user, then send the DCN with
"to":" < this user > "