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)

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

MessageType Rejection Code Description
All Error occurred while creating job Server-side Error
All Missing Sender Empty 'Sender' field
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 target(s) found, ie. if MessageType is Fax, there is no destination fax number listed
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.

 

The REST API will only error when fields are missing values for formatting.
The REST API will accept API calls with invalid or incorrect data; this is validated and an error is produced after the data is accepted.