Topic
Open-source startups tagged #mail
8 open-source startups in this directory carry the GitHub topic #mail. 7 pushed code within 30 days of the snapshot of 2026-09-22, 1 has been quiet for 31–120 days, 0 have 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 8 pushed within 30 days of the snapshot of 2026-09-22. How we measure it →
The list
All 8, 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 |
|---|---|---|---|---|
| docker-mailserver/docker-mailserver | Production-ready fullstack but simple mail server (SMTP, IMAP, LDAP, Antispam, Antivirus, etc.) running inside a container. | 18.9K | Still shipping | Sep 22, 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 |
| postalserver/postal | 📮 A fully featured open source mail delivery platform for incoming & outgoing e-mail | 16.8K | Still shipping | Sep 19, 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 |
| stalwartlabs/stalwart | All-in-one Mail & Collaboration server. Secure, scalable and fluent in every protocol (IMAP, JMAP, SMTP, CalDAV, CardDAV, WebDAV). | 14.8K | Still shipping | Sep 21, 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 |
| mailcow/mailcow-dockerized | mailcow: dockerized - 🐮 + 🐋 = 💕 | 13.5K | Still shipping | Sep 21, 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 →