Thunderbird is a free and open-source email, calendaring, newsfeed, and chat client with more than 20 million active monthly users across Windows, macOS, and Linux.Ĭurrently, Android mobile users have a number of email and chat options, including Google’s Gmail, Microsoft Outlook, and ProtonMail, an end-to-end encrypted email service. (Ketterer is better known in the Mozilla open-source developer community as cketti.) “Ultimately, K-9 Mail will transform into Thunderbird on Android, once certain development milestones have been achieved which align it closely with Thunderbird's feature set and visual appearance,” K-9 Mail Project Maintainer Christian Ketterer said in a blog post. (K-9 Mail is available for download through these various sites.) Those planned improvements include account setup using Thunderbird account auto-configuration, as well as folder management, support for message filters, and synchronization between desktop and mobile versions of Thunderbird, Mozilla said.

The development team for MZLA Technologies plans to improve the email feature set to more closely resemble that of its Thunderbird desktop email client.

Thunderbird email app