populate "to" phoneNumber for incoming fax messages
For SMS and VoiceMail incoming message types, the "to" array's "phoneNumber" is populated with the proper phone number that the message was sent to. BUT, for incoming Fax messages the "to" phoneNumber is populated into the "subject" element and the "to""phoneNumber" element is not populated at all. Based on the API documentation, this is not correct. Can this be corrected in a future version of the API?