listmonk is a self-hosted email campaign and mailing list manager beloved by privacy-conscious marketers and developers. This high-performance platform handles everything from newsletter management to transactional emails, featuring subscriber segmentation, bulk importing, and multi-SMTP support. With its intuitive interface, users can create campaigns using WYSIWYG editors or raw HTML, track performance metrics, and ensure GDPR compliance. The single-binary application offers extensive customization through Go templating and webhook integrations.

If you want ultimate control over your email campaigns and subscriber data, listmonk delivers. Its self-hosted, open-source model puts you fully in charge, with high-speed sending, customizable templates, and robust subscriber management. We found the ability to segment lists using SQL and automate transactional emails via API especially powerful for businesses handling sensitive data or needing tailored mass communications—think membership sites, SaaS apps, or niche publishers.

The required self-hosting, PostgreSQL setup, and SMTP configuration demand technical know-how, and there’s a clear lack of analytics for transactional emails. Privacy features like unsubscribe handling also require manual setup. If technical complexity doesn’t faze you, listmonk’s flexibility and zero price tag are hard to beat. Just be ready for some hands-on administration.

Improve your customer retention by using listmonk's transactional email feature and API to automatically send personalized onboarding sequences triggered by user actions within your app. For example, when a new user signs up, trigger a sequence of emails introducing key features, offering helpful tips, and prompting them to complete their profile. This proactive engagement can significantly increase user activation and reduce churn by providing timely and relevant support.