The status codes returned by the Dyn Email API are:

• 200 - OK— The action was successful.
• 404 - Not Found— This message means that the client successfully connected to the server, but the server could not complete the requested action, likely because the server could not find the requested information.
• 503 - Service Unavailable— The server is currently unavailable. It could be overloaded or just down for maintenance, but this is just temporary. Try again in a short while.
• 451 - Missing or Invalid API Key— The API key is either missing or incorrect. Reconfirm the API key or, if necessary, you can generate (or re-generate) an API key from the edit/create user page.
• 452 - Missing or Invalid Required Fields— Required fields are marked with a red asterisk (). This error could also come up if the input is in an invalid form (i.e., letters instead of numbers, etc.).
• 453 - Object Already Exists— This error can come up if you try to create an account that already exists.