One of the most popular alternatives to Thunderbird is Betterbird, which is free and open source. Other popular alternatives are K-9 Mail, Evolution, Microsoft Outlook and SeaMonkey. There's no shortage of Email Clients like Thunderbird, with more than 100 alternatives for Windows, Mac, Linux, Android and iPhone.
Email and news client on GTK+ foundation featuring quick performance, extensible plugins, secure protocols, advanced filtering, strong folder and contact management, lightweight design, powerful search, customizable interface, multi-language support, and encryption.
Melia is a modern, privacy-first email client for Linux. It keeps your mail on your own machine instead of in the cloud, connecting straight to your IMAP and SMTP servers and storing everything in a local database.
United States
Modern open-source email client supporting unified inbox, IMAP/SMTP, Gmail and Outlook with OAuth2, conversation threading, rich text TipTap composing, CardDAV contact sync, tracking removal, dark mode, color themes, vim-style shortcuts, and a detachable window.
Hong Kong
Geary is an email application built around conversations, for the GNOME 3 desktop.
United States
Secure email app for Mac, iPhone, Android and Windows with AI Copilot, PGP encryption, read receipts and one unified inbox.
Singapore
Mailpile is a modern, fast web-mail client with user-friendly encryption and privacy features. The development of Mailpile is funded by a large community of backers and all code related to the project is and will be released under an OSI approved Free Software license.
Android email app focused on privacy and security, supporting JMAP, IMAP, and SMTP protocols, encrypted credentials, OpenPGP through OpenKeychain, unified inbox, conversation threading, offline mode, strong tracking protection, F-Droid distribution, no ads or Google dependence.
BlueMail is a modern, mobile first, powerful Email management tool with a sleek design, unified inbox and support for all your accounts: IMAP,Exchange,POP3.
United States
Japan
KMail is the email component of Kontact, the integrated personal information manager of KDE. Kontact is a personal information manager and groupware software suite for KDE. It supports calendars, contacts, notes, to-do lists, news, and email.
Germany
EU
TypeApp is an all-free, beautifully designed, universal email app, capable of managing unlimited number of mail accounts from various providers, allowing for smart push notifications while enabling personalization across multiple email accounts.
United States
Transform your email inbox into a collaborative workspace with Spike. Enjoy integrated chat-like emails, tasks, collaborative notes, and group projects. Seamlessly manage multiple accounts, organize priorities, and schedule meetings across devices.
Israel
