The Maileon API returns an HTTP status code to each request. For most error cases, the response body is an XML errors document containing more details.

Successful 2XX

Client Error 4XX

Server Error 5XX

Example Error Report

Status: 400 Bad Request
Content-Type: application/vnd.maileon.api+xml

<?xml version="1.0" encoding="UTF-8"?>

<message>page_size must not exceed 1000 but was 200000</message>