Why Thunderbird? Thunderbird is one of the world's most trusted open-source email applications, empowering more than 20 million people globally. At MZLA, the team behind Thunderbird, we build privacy-respecting communication and productivity tools that help people manage their digital lives while staying in control of their data. We are open source by design. Our products are developed transparently and in collaboration with a global community of contributors, and that same spirit shapes how w