post https://sandbox.datamotion.com/SecureMessagingApi/Message//Move
This method is used to move a particular message into a specific folder. Messages can only be moved within their respective type (ie: Inbox or Outbox), but they can be placed in any subfolder with the same type. A session key must be submitted via the X-Session-Key header. The message ID of the message you'd like to move must be passed in the URL of this method. The response body will be empty. A successful transaction will receive a 200 status code.