Thunderbird is described as 'Cross-platform email client providing POP/IMAP support, robust filtering, multiple accounts, and chat. Extendable via add-ons with RSS/Atom, etc' and is a leading Email Client in the office & productivity category. There are more than 50 alternatives to Thunderbird for a variety of platforms, including Windows, Mac, Linux, Android and iPhone apps. The best Thunderbird alternative is K-9 Mail, which is both free and Open Source. Other great apps like Thunderbird are Claws Mail, Evolution, Betterbird and SeaMonkey.
Engineered for iOS, macOS, and watchOS, this fast mail client supports multiple account types, custom actions, Smart Inbox filtering, unified inbox, privacy mode, email scheduling, snooze, third-party app integration, flexible personalization, and advanced workflow tools.
ElectronMail is an Electron-based unofficial desktop client for ProtonMail and Tutanota end-to-end encrypted email providers. The app aims to provide enhanced desktop user experience enabling features that are not supported by the official in-browser web clients.
Trojitá, is a fast Qt IMAP e-mail client that respects open standards and facilitates modern technologies. Trojitá values vendor-neutrality that IMAP provides and is committed to be as interoperable as possible.
The free Zimbra Desktop client allows you to meld the online and offline worlds – storing and synching your email, calendar, contacts, files and documents in the cloud, yet having them locally accessible when on the road.
Wino is a lightweight native mail client for Windows 10/11. It is still in active development. Main motivation for this project is to replace Mail & Calendar for Windows with modern Windows design without using web technologies for speed.
Collaborative email and threaded group chat for productive teams. A single app for all your internal and external communication.
aerc is an email client that runs in your terminal. It's highly efficient and extensible, perfect for the discerning hacker.
Foxmail is a free POP3 and IMAP4 e-mail client in English and Chinese for Windows systems.
The most powerful platform for email productivity in a beautiful native app — on desktop and mobile.
Shortwave is an email app that takes the pain out of managing your inbox, making it effortless to stay organized, productive, and responsive.
An enterprise application server that integrates information into a single workspace, integrates also a full mail server
Italy
EU
Czechia
United States
Türkiye
Germany
Canada
China
India
Thunderbird connects with servers that use standard protocols and with servers for which a plugin was developed. ElectronMail works with ProtonMail ONLY and was specifically designed for this provider. Tutanota support is deprecated since July 2019.