BillionMail — Open-Source Self-Hosted Mail Server & Newsletter Platform

Introduction

BillionMail is an open-source, self-hosted mail server that bundles a full email infrastructure with newsletter and email marketing tools. It combines Postfix for SMTP, Dovecot for IMAP, and Rspamd for spam filtering into a single Docker Compose deployment, eliminating monthly fees from services like Mailchimp or SendGrid.

What BillionMail Does

• Provides a complete mail server with SMTP, IMAP, and webmail access out of the box
• Includes a newsletter editor with drag-and-drop template builder and subscriber management
• Handles email marketing campaigns with scheduling, segmentation, and analytics
• Filters spam and malware using Rspamd with automatic DKIM, SPF, and DMARC configuration
• Manages multiple domains and mailboxes through a clean web admin interface

Architecture Overview

BillionMail runs as a set of Docker containers orchestrated via Docker Compose. Postfix handles outbound and inbound SMTP, Dovecot provides IMAP access, and Rspamd performs spam filtering and DKIM signing. A Go-based API server powers the admin dashboard and newsletter engine. MariaDB stores configuration, subscriber lists, and campaign data. An optional webmail container provides browser-based email access.

Self-Hosting & Configuration

• Requires a VPS or server with ports 25, 143, 443, 587, and 993 open, plus a valid domain with proper DNS records
• Set MAIL_DOMAIN, ADMIN_PASSWORD, and DB_PASSWORD in the .env file before first launch
• Run docker compose up -d to start all services; the setup wizard configures DNS records
• Add DKIM, SPF, and DMARC DNS records as shown in the admin panel for deliverability
• Configure Let's Encrypt certificates automatically via the built-in ACME client

Key Features

• All-in-one solution: mail server plus newsletter platform in a single deployment
• Zero recurring costs compared to hosted email marketing services
• Built-in deliverability tools with DKIM/SPF/DMARC setup guidance and warm-up scheduler
• Privacy-respecting analytics for email opens, clicks, and bounces without third-party trackers
• Multi-domain support with per-domain settings and quota management

Comparison with Similar Tools

• Mailcow — Full-featured mail server but lacks built-in newsletter/marketing tools
• Mailu — Lightweight mail server; BillionMail adds campaign management and subscriber analytics
• Listmonk — Newsletter-only tool requiring a separate mail server; BillionMail bundles both
• Mautic — Marketing automation platform but needs external SMTP; BillionMail is self-contained
• iRedMail — Script-based install; BillionMail uses Docker for easier deployment and updates

FAQ

Q: Does BillionMail handle transactional email? A: Yes. It provides SMTP credentials for application use alongside marketing campaigns, with separate sending pools to protect deliverability.

Q: What are the minimum server requirements? A: A VPS with 2 GB RAM, 2 CPU cores, and 20 GB storage handles thousands of mailboxes. More storage is needed for large inboxes.

Q: Can I import subscribers from another platform? A: Yes. The admin panel supports CSV import for subscriber lists with field mapping and deduplication.

Q: Is there rate limiting for outbound email? A: Yes. BillionMail includes configurable rate limits per domain and per campaign to maintain sender reputation and comply with ISP guidelines.

Sources

• https://github.com/Billionmail/BillionMail
• https://www.billionmail.com