listmonk

Listmonk is a high-performance email delivery and newsletter management platform. It handles smooth delivery to subscriber lists of hundreds of thousands while providing full control over email infrastructure through self-hosting.

• High-speed delivery with multi-threaded processing for bulk email campaigns
• Rich editor with WYSIWYG/HTML editing and template management
• Segmentation for grouping subscribers by attributes and behavior for targeted campaigns
• Campaign analytics tracking open rates, click rates, and bounce rates
• REST API for automating mailing list and subscriber management
• Double opt-in with GDPR-compliant confirmation email subscription flows

Built in Go as a single binary with PostgreSQL, Listmonk uses minimal resources. It provides a self-hosted Mailchimp alternative that dramatically reduces email delivery costs.