Listmonk
Self-hosted newsletter and mailing list manager: one Go binary plus PostgreSQL, millions of subscribers, zero per-subscriber fees.
About
Listmonk is a standalone, self-hosted newsletter and mailing list manager by Kailash Nadh (CTO of Zerodha, India's largest stock broker, which runs it in production). The whole stack is one Go binary plus a PostgreSQL database, delivered free under AGPL v3, and it is built for raw performance: a production instance reportedly sent a 7-million-email campaign on a fraction of one CPU core with 57 MB of peak RAM. It handles millions of subscribers across unlimited lists, campaigns with built-in analytics, a full REST API, GoTemplate+Sprig email rendering, multi-tenant SMTP routing, bounce processing, and A/B testing.
The honest caveats matter. Listmonk manages and sends, but actual delivery goes through an SMTP provider you connect (Amazon SES, Mailgun, Brevo, or your own server), so high-volume sending still carries the provider's (much smaller) cost. Deliverability is your job: SPF, DKIM, and DMARC on your sending domain, or your newsletters land in spam. And the AGPL v3 license means if you modify the code and host the modified version, you must open-source those changes. The project is actively maintained, with v6.2.0 shipped in June 2026, and it powers newsletters at Mozilla, Krea AI, and hundreds of independent publishers.
What it can do
- Unlimited subscribers and lists
- Campaign creation with analytics
- Full REST API
- Transactional email API
- GoTemplate+Sprig email rendering
- Bounce processing
- Click and open tracking
- A/B testing
- Double opt-in subscription forms
- Multi-SMTP routing
- OAuth2 SSO
Setup
Install PostgreSQL, download the listmonk binary (or docker compose up), configure your SMTP provider, and open http://localhost:9000.
Prerequisites
PostgreSQL database; an SMTP provider (e.g. Amazon SES) for actual delivery; SPF/DKIM/DMARC DNS records for deliverability.
Use cases
Works with
Trust score — 8/10
Scored 8/10 (TIER verified, metrics-v1). Evidence: open-source codebase fully inspectable on GitHub (~22,200 stars); docs, license (AGPLv3), and performance claims documented across the repo and independent write-ups; production use at Mozilla and Krea AI reported. Strengths: extreme efficiency and zero per-subscriber cost, clean single-binary deployment, active maintenance (v6.2.0, June 2026). Docked for: (1) performance figures (7M emails, 57MB RAM) are provider/community-reported without published independent benchmarks; (2) deliverability is entirely the operator's responsibility; (3) AGPL v3 is copyleft — modification-hosting requires publishing changes. License: AGPL-3.0; free software, self-hosted.
★ 22,200 GitHub stars
How the trust score is built
Full methodology →- Adoption · stars/downloads, log-scaled vs peers
- 7.0/10
- Maintenance · recency, releases, issue load
- 8.0/10
- Openness · license + docs
- 9.0/10
- Manual review · sanity read + red-flag check
- 8.0/10
- · By Kailash Nadh (CTO of Zerodha); ~22,200 GitHub stars
- · Single Go binary + PostgreSQL; v6.2.0 shipped June 2026
- · Production use at Mozilla and Krea AI reported
- · 7M-email campaign performance figures provider/community-reported, not independently benchmarked
- · Deliverability is the operator's job (SPF/DKIM/DMARC required)
Sources
Every fact above was checked against these sources. Where a claim comes from the provider and couldn't be independently verified, the text says so.