The platform handles the full email campaign lifecycle: subscriber management with custom attributes and segmentation, campaign creation with a rich HTML template editor, scheduling and throttled sending, bounce processing, click and open tracking, and analytics dashboards. It supports both newsletter broadcasts and transactional email via its REST API, making it suitable for both marketing and application-driven email workflows.

Listmonk is designed to handle scale efficiently. It can manage millions of subscribers with its sliding-window message queue that throttles delivery to respect SMTP provider rate limits. The platform supports multiple SMTP servers with round-robin distribution, enabling high-throughput sending across multiple email providers. Campaign templates use Go’s template engine with variables for personalization, conditional content blocks, and dynamic subscriber attributes.

The REST API enables programmatic subscriber management (create, update, query, segment), campaign creation and scheduling, list management, template CRUD, and analytics retrieval. This makes it straightforward for AI agents to automate email workflows: adding subscribers from form submissions, triggering campaigns based on events, segmenting lists based on behavior data, and generating campaign performance reports. The API uses standard JSON over HTTP with token-based authentication.

Installation options include a single Docker Compose file (docker compose up -d), direct binary download from GitHub releases, or package manager installation. The built-in web UI provides a modern dashboard for managing all operations visually. Listmonk supports internationalization, S3-compatible media storage for email assets, and webhook integrations for delivery events. The project was originally developed by Zerodha, India’s largest stock broker, for their own email infrastructure needs.