See TNZ API documentation: REST API, SOAP API, .NET Library, HTTP/S API, SMTP API
REST API MessageTypes: SMS, Email, Fax, Voice, Text-to-Speech (TTS)

APIs perform only simple form validation on receipt of your API call; it won't validate the content of your message or the Sender/APIKey validity when accepting the call. These are validated by our authentication engine after receiving the API call and reported to the API user's administrator as an email to the listed 'API Error Email Notify' email address (viewable in your Dashboard login). This is to achieve optimum resiliency and speed, and to provide a layer of protection against API brute force attacks.

When submitting messages to the REST API, possible rejection codes are:

MessageType Rejection Code Description
All Error occurred while creating job Server-side error. Try again, or contact us if the error persists.
All Missing Sender Empty 'Sender' field or your API call is malformed and we can't find the 'Sender'
All Missing APIKey Empty 'APIKey'
All Invalid sender format 'Sender' is not an email address
All Missing message data Empty 'MessageData' field
All Missing or empty destinations Target(s) not found
All Error - Could not find any valid destination(s). No valid targets found in the Destination section, ie. if MessageType is SMS, there is no mobile number listed as a Recipient in 'Destinations'
All WebhookCallbackURL must start with https:// You will need to include the full path including the https:// prefix in your custom WebhookCallbackURL value (http:// is not supported)
Fax Missing file name on file x MessageData.Files listed without a valid 'Name'
Fax Missing file data on file x MessageData.Files listed without valid 'Data'
Fax Missing fax contents - Empty or missing message & file fields MessageData.Message and/or MessageData.Files fields are not found
SMS Message(s) NOT found GET Poll is unable to find messages (result and reply tracking)
SMS Missing or empty message Empty MessageData.Message field
Email Missing or empty message body. Please specify MessagePlain or MessageHTML Empty MessageData.MessagePlain field and/or MessageData.MessageHTML field
Voice/TTS Missing message to people Empty MessageData.MessageToPeople field
Voice/TTS Missing tone on keypad x MessageData.Keypads are listed without a corresponding 'Tone' value
Voice/TTS Invalid tone on keypad x. Tone must be between 0~9 MessageData.Keypads.Tone is listed but is out of the valid range (value must be 0-9)
Voice/TTS Missing RouteNumber/Play on keypad x MessageData.Keypads are listed without corresponding 'RouteNumber' and 'Play' fields
Voice/TTS Invalid RouteNumber format on keypad x MessageData.Keypads.RouteNumber exists but the route number is invalid (or incorrectly formatted). It must be greater than 9 digits and numeric.