Thunderbird Overview
Thunderbird is a free, open-source email application for Windows, macOS, and Linux, developed by the Thunderbird project (part of Mozilla). It brings multiple email accounts together in one place and works with standard IMAP, POP, and SMTP, so it can connect to virtually any provider, from Gmail and Outlook.com to private and corporate mail servers. Beyond email, it is a full personal-information manager with an integrated calendar, task list, and contacts, plus support for RSS news feeds and chat. Powerful message filters, tagging, saved searches, and a unified inbox keep large amounts of mail organized, while built-in OpenPGP encryption and phishing protection help keep messages private and safe. A long-standing add-on system lets you extend and theme the program, and because it stores mail locally, your messages remain available and searchable on your own computer. The full offline installer holds the complete application, so it sets up on a machine with no internet connection. This page links to the official Thunderbird download.