Topic
Open-source startups tagged #email
9 open-source startups in this directory carry the GitHub topic #email. 7 pushed code within 30 days of the snapshot of 2026-09-22, 1 has been quiet for 31–120 days, 1 has not pushed in over 120 days. Topics are set by each repository’s own maintainers, so this is what those projects chose to call themselves rather than a category we assigned.
7 of 9 pushed within 30 days of the snapshot of 2026-09-22. How we measure it →
The list
All 9, most-starred first.
The last column is the most recent push GitHub reported to us on 2026-09-22. It counts a push to any branch, by a person or a bot — it is not a claim that anyone is maintaining the project, and a quiet repository may be a finished one.
| Project | What it does | Stars | Ship status | Last verified push |
|---|---|---|---|---|
| novuhq/novu | The open-source communication infrastructure for agents and products | 40K | Still shipping | Sep 22, 2026 |
| nylas/nylas-mail | :love_letter: An extensible desktop mail app built on the modern web. Forks welcome! | 24.7K | Gone silent | Jun 25, 2026 |
| Foundry376/Mailspring | :love_letter: A beautiful, fast and fully open source mail client for Mac, Windows and Linux. | 17.8K | Still shipping | Sep 22, 2026 |
| aaPanel/BillionMail | BillionMail gives you open-source MailServer, NewsLetter, Email Marketing — fully self-hosted, dev-friendly, and free from monthly fees. Join the discord: https://discord.gg/asfXzBUhZr | 15.6K | Slowed | Jun 11, 2026 |
| mail-in-a-box/mailinabox | Mail-in-a-Box helps individuals take back control of their email by defining a one-click, easy-to-deploy SMTP+everything else server: a mail server in a box. | 15.4K | Still shipping | Sep 1, 2026 |
| logto-io/logto | 🧑🚀 Authentication and authorization infrastructure for SaaS and AI apps, built on OIDC and OAuth 2.1 with multi-tenancy, SSO, and RBAC. | 14.6K | Still shipping | Sep 22, 2026 |
| maillab/cloud-mail | A Cloudflare-based email service | 基于 Cloudflare 的邮箱服务 | Cloudflare Email 邮箱 Mail | 14.3K | Still shipping | Sep 5, 2026 |
| thunderbird/thunderbird-android | Thunderbird for Android – Open Source Email App for Android (fka K-9 Mail) | 14K | Still shipping | Sep 22, 2026 |
| elie222/inbox-zero | The world's best AI personal assistant for email. Open source app to help you reach inbox zero fast. | 12.3K | Still shipping | Sep 22, 2026 |
Related collections
Sideways from here.
The 8 largest other topics in the directory, then the other ways to slice it. Every count is as of the snapshot of 2026-09-22.
Snapshot of 2026-09-22 · 721 repos in the directory · every number on this page is measured against that date, not against today. What this measurement cannot tell you →