# Foundry376/Mailspring

:love_letter: A beautiful, fast and fully open source mail client for Mac, Windows and Linux.

Repository: https://github.com/Foundry376/Mailspring
Canonical: https://ross.abutalabs.com/products/mailspring
Homepage: https://getmailspring.com/
Language: JavaScript
License: GPL-3.0
License Family: copyleft
Topics: email, mail, electron, osx, windows, linux, electron-app, imap
Last push: 2026-08-26T19:08:42+00:00

## Health v2 (maintenance only)
Score: 97/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 94, longevity 100
- inputs: {"age_days": 3611, "days_push": 7, "days_rel": 42, "gap_med": 14, "n_releases_24m": 18}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 17761, forks 1023 (observed 2026-08-28T04:11:20.346552+00:00)

## What it is
Mailspring is a fully open source desktop email client for Mac, Windows, and Linux, built with Electron, React, and TypeScript, with a C++ sync engine based on Mailcore2. It supports IMAP, Gmail, Office 365, and other major providers with features like unified inbox, snooze, send later, templates, and a plugin/theme architecture.

## Use cases
- manage multiple email accounts in one unified inbox
- schedule emails to send later
- snooze emails and set follow-up reminders
- search across all connected mail accounts
- customize an email client with plugins and themes
- use a free open-source alternative to Outlook or Spark
- track read receipts and link clicks on sent email

## When to choose
- you want a beautiful, fast, cross-platform desktop mail client that is open source
- you need IMAP/SMTP or Office 365 support with local sync and credentials kept on-device
- you want to extend or theme your email client via a plugin architecture

## When to avoid
- you need a mobile email client (Mailspring is desktop-only)
- you require calendar or contact sync beyond basic support
- you want a fully free product including read receipts and link tracking (those require the paid Pro subscription)

## Facets
- artifact type: application
- maturity: active
- function: email, gui, search-engine, plugin-system
- domain: email, developer-tools, cross-platform, desktop-applications
- platform: windows, cross-platform
- tags: mail-client, imap, smtp, unified-inbox, open-source-email, react, typescript, sync-engine, macos, linux, electron

## Member repositories
- Foundry376/Mailspring (main) score 97

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:11:20.346552+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:02:28.080714+00:00, confidence not recorded.
  - readme: https://github.com/Foundry376/Mailspring (fetched 2026-08-28T04:11:20.346552+00:00, sha 8ffa304ed852)
  - homepage: https://getmailspring.com/ (fetched 2026-08-29T08:00:59.411939+00:00, sha f1114ae33088)
  - site_page: https://www.getmailspring.com/changelog (fetched 2026-08-29T08:00:59.421099+00:00, sha 15fa67132464)
  - site_page: https://www.getmailspring.com/pro (fetched 2026-08-29T08:00:59.423119+00:00, sha b283d32efeba)
- Data as of 2026-08-30T08:39:29.467469+00:00.