Best Email Clients & Webmail tools by public signals

These picks are computed from scored public evidence. Use the openness column in the ranking to separate OSI-approved, source-available, open-core, proprietary, and unverified-license tools.

Use Case Rankings

Ordered by ToolVitals score, then health, shipping, confidence, GitHub stars, and name.

#ToolHealthShippingOpennessStarsScoreStatus
01thunderbird-android
Thunderbird for Android – Open Source Email App for Android (fka K-9 Mail)
9898OSI-approved OSS14k98Active
02Inbox Zero
The world's best AI personal assistant for email. Open source app to help you reach inbox zero fast.
9797OSI-approved OSS12.2k97Active
03Bulwark Mail
Self-hosted JMAP webmail client for modern mail servers.
9797OSI-approved OSS1.1k97Active
04Mailflow
Self-hosted unified webmail client.
9697OSI-approved OSS45596Active
05eGroupware
Web-based groupware server for calendars, contacts, webmail, and project collaboration.
9497OSI-approved OSS29695Active
06Mailspring
:love_letter: A beautiful, fast and fully open source mail client for Mac, Windows and Linux.
9593OSI-approved OSS17.8k94Active
07FreshRSS
A free, self-hostable news aggregator…
9490OSI-approved OSS16k93Active
08FairEmail
Fully featured, privacy-friendly email app for Android.
8693OSI-approved OSS4.6k89Active
09neomutt
✉️ Teaching an Old Dog New Tricks -- IRC: #neomutt on irc.libera.chat
9086OSI-approved OSS3.8k88Active
10NeoMD
Minimal email TUI where you read with Markdown and write in Neovim.
7982OSI-approved OSS26981Active
11matcha
A beautiful and functional email client for your terminal, built with Go and the charming Bubble Tea TUI library. Never leave your command line to check your inbox or send an email again!
7862OSI-approved OSS1.1k71Active
12Afterlogic Webmail Lite 8
Open-source webmail client for existing IMAP servers.
6657OSI-approved OSS36262Warning
13Mail0
Experience email the way you want with Mail0 – the first open source email app that puts your privacy and safety first. Join the discord: https://mail0.link/discord
160OSI-approved OSS10.8k10Critical

Not Scored

Tracked for context, but excluded from rankings because comparable open/source-visible evidence is unavailable.