Best Free Email Clients (2026)

Mozilla Thunderbird

The Mozilla Foundation

Freeware v149.0.2 74MB

4.0

5 reviews

Thunderbird is a free, open source email client by MZLA Technologies (a subsidiary of the Mozilla Foundation). It handles email, calendars, contacts, and tasks in one application. It supports IMAP, POP3, CalDAV, CardDAV, and has been adding Exchange support. Licensed under the Mo...