The Messages API is a REST API that allows developers to get details about any outbound or inbound messages processed through their Postmark server. The API supports search functionality using query parameters, but each search can only return up to 10,000 messages. To retrieve message data for more than 10,000 messages, developers need to use search parameters to narrow down the results. This tutorial provides two examples of breaking down larger sets of messages into chunks of less than 10,000 using node.js and exporting the results as a CSV file. The first example retrieves message data by tag, while the second example retrieves message data by date range. Developers can execute their app using the `node index.js` command and modify the code to support other valid search parameters, wider or narrower time ranges, saving results to a database, or using the official Postmark node.js library.