21211: Invalid 'To' Phone Number
21408: Your account is not allowed to send SMS to this country or region.
21614: 'To' number is not a valid mobile number
21635: The "To" number is a landline and cannot receive SMS.
21661: 'From' number is not SMS-capable
30002: Message failed: your account is currently suspended.
30003: Number unreachable or out of service.
30004: Recipient has opted out or has DND enabled.
30005: The recipient’s number is inactive or does not exist.
30006: Landline or unreachable carrier
