listmonk - Free and open source self-hosted newsletter, mailing list manager, and transactional mails | WarmIndex

Listmonk is a free, open-source, high-performance self-hosted newsletter, mailing list, and transactional email manager designed for developers and organizations seeking full control and privacy.

🚀 Overview

Listmonk is a standalone, self-hosted application that packs powerful newsletter and mailing list management into a single binary, offering high performance and feature richness without the bloat of SaaS alternatives.

It solves the problem of expensive, privacy-invasive hosted services like Mailchimp by providing a lightweight, scalable solution that handles millions of subscribers, SQL-based segmentation, real-time analytics, and high-throughput email queues—all while running on minimal resources (e.g., a production instance sending 7M+ emails uses a fraction of one CPU core and 57MB RAM).

Built for developers, indie makers, and teams who value self-hosting, data sovereignty, and extensibility. I built it to create a modern, single-binary alternative that's easy to deploy anywhere, with extensive API coverage, templating, and support for transactional mails and messengers like SMS/WhatsApp.

✨ Key Features

High-performance mailing lists: Manage millions of subscribers with single/double opt-in, SQL querying/segmentation, and multi-threaded SMTP queues with rate limiting.
Built-in analytics: Visualize campaign performance, bounces, top links, and more.
Advanced templating: Use Go templating language with logic, 100+ functions, drag-and-drop builder, WYSIWYG, Markdown, or raw HTML for dynamic emails.
Transactional emails & extensibility: API for transactional mails; messenger webhooks for SMS, WhatsApp, FCM; full API coverage.
Privacy & security: Full subscriber privacy controls, OIDC SSO, granular roles/permissions, API tokens.
Optional: Media library with S3 backend, internationalization.