BillionMail is an open-source, self-hosted solution that combines a full mail server (SMTP, IMAP/POP3) with email marketing and newsletter capabilities. Designed for businesses and developers seeking full control over their email infrastructure, it eliminates reliance on third-party services like Mailchimp or SendGrid. Built with Go and integrating Postfix, Dovecot, and Rspamd, BillionMail provides a complete stack for sending transactional emails, newsletters, and managing email campaigns—all without subscription fees or data privacy concerns. It’s ideal for teams that need to comply with data sovereignty laws, avoid vendor lock-in, or scale email operations without recurring costs.
The platform simplifies deployment with a one-click installer and Docker support, while offering integrated WebMail via RoundCube. With features like DNS record auto-verification, SSL certificate management, and real-time campaign analytics, BillionMail targets users who want enterprise-grade email functionality without the complexity or cost of proprietary alternatives.
What You Get
- Full Mail Server Stack - Integrates Postfix (SMTP), Dovecot (IMAP/POP3), and Rspamd (spam filtering) for a complete, self-hosted email infrastructure with no external dependencies.
- Email Marketing & Newsletter Tools - Create, schedule, and send email campaigns with customizable templates, list segmentation, and tag-based targeting.
- Advanced Email Analytics - Track delivery status, open rates, click-through rates, and bounce reports directly within the dashboard.
- Auto-Domain Configuration - Automatically verifies DNS records (SPF, DKIM, DMARC) and enables free SSL certificates upon domain addition.
- Integrated WebMail (RoundCube) - Access your mailboxes via a web interface at /roundcube/ without needing separate installation.
- Self-Hosted & Zero Monthly Fees - Run entirely on your own server; no usage limits, subscriptions, or data sharing with third parties.
- One-Click Installation - Deploy in under 8 minutes using bash script or Docker with pre-configured compose files and .env templates.
Common Use Cases
- Building a private email marketing platform for SaaS startups - A startup wants to send newsletters and onboarding emails without paying per-email fees or exposing customer data to third-party platforms.
- Managing high-volume transactional emails for an e-commerce platform - An online retailer needs to send order confirmations, shipping updates, and promotional emails with full delivery tracking and spam filtering.
- Problem: High costs from SendGrid/Mailchimp → Solution: Self-hosted BillionMail - A company spends $500+/month on email services; migrating to BillionMail reduces costs to zero while improving data control and delivery reliability.
- DevOps teams managing email infrastructure across multiple environments - Teams deploy BillionMail on-premises or in private clouds to ensure compliance with GDPR, HIPAA, or other data residency requirements.
Under The Hood
This project is a comprehensive email infrastructure management system that combines a robust Go backend with a modern Vue.js frontend, designed for scalable and configurable email handling. It emphasizes modular architecture, extensive automation, and integration capabilities across various services and AI providers.
Architecture
It adopts a monolithic structure with clear separation between backend and frontend, ensuring organized layers and well-defined modules.
- Modular organization with distinct components for API, batch mail, AI integration, and recipient management
- Layered design separating business logic, data access, and presentation concerns
- Support for containerized deployment through hybrid scripting and Go-based core services
Tech Stack
It leverages a modern tech stack with Go powering the backend and Vue 3 for the frontend, supported by a rich ecosystem of tools.
- Built with Go for backend services and Vue 3 + TypeScript for the user-facing interface
- Extensive use of UI libraries like naive-ui and state management via pinia
- Rsbuild as the build system with Sass, ESLint, and Unocss for styling and linting
Code Quality
The codebase reflects a mixed quality profile with strengths in backend consistency and configuration but limited test coverage.
- Strong emphasis on Go-based backend services with clear structure and error handling
- Minimal automated testing and limited test file presence across the codebase
- Code linting and formatting practices are in place but not fully enforced
What Makes It Unique
It distinguishes itself through modular configuration, hybrid development practices, and deep AI integration capabilities.
- Modular configuration system with dedicated directories for Dovecot, Postfix, and Rspamd
- Hybrid development approach combining Go logic with shell scripts for deployment automation
- Extensive supplier integration framework supporting multiple AI providers for content analysis
- File watching and hot-reload mechanisms enable rapid iteration without manual container restarts