Thunderbird
Thunderbird is a free, open-source email client developed by the Mozilla Foundation that allows users to manage multiple email accounts, contacts, and calendars in a single application. It supports features like email filtering, encryption, and add-ons for customization, making it a versatile tool for personal and professional communication. Originally based on the same code as Firefox, it provides cross-platform compatibility on Windows, macOS, and Linux.
Developers should learn or use Thunderbird when they need a robust, privacy-focused email client for managing multiple accounts, especially in environments where open-source tools are preferred or when integrating with custom workflows via add-ons. It is particularly useful for handling email in development teams, automating tasks with filters, or securing communications with encryption, such as in freelance or remote work settings.