Using the Nylas Ruby API and Sinatra micro-framework, this guide demonstrates how to create a web application that organizes email threads by grouping related messages while removing extraneous information. It provides a step-by-step process, beginning with setting up the Ruby environment and installing necessary gems like Sinatra, Puma, and Nokogiri. The application features a single input field for users to enter an email address, which then retrieves all related email threads containing at least two messages. The emails are displayed in a collapsible accordion format, showing messages sequentially with contact images while filtering out noise such as emails, phone numbers, and reply texts. The application requires setting up a specific folder structure, including "views" and "public" folders, and involves coding components for initializing the Nylas API client, cleaning email content, and managing contacts and images. Once configured, the application runs on localhost, allowing users to view and interact with their threaded emails through a browser interface.