Mail-in-a-Box

Mail-in-a-Box is an open-source mail server appliance that automates the deployment of SMTP, IMAP, and DNS services. It transforms a fresh Ubuntu 22.04 LTS 64-bit machine into a fully functional email server through a scripted installation process that handles the installation and configuration of various underlying components.

The software is deployed as a server application and includes a web-based control panel for administration. It is designed for individuals who want to manage their own email infrastructure without manually configuring individual server components. By automating the setup of the mail stack, it removes the need for manual configuration of complex mail protocols. It also supports static website hosting for the domains managed on the box since the system already serves HTTPS traffic.

Key features

• Automated installation of Postfix for SMTP and Dovecot for IMAP
• Integrated DNS server with SPF, DKIM, DMARC, and DNSSEC records
• Automatic TLS certificate provisioning via Let's Encrypt
• Built-in webmail interface using Roundcube
• Spam filtering and greylisting via SpamAssassin and Postgrey
• CardDAV and CalDAV support through Nextcloud
• System protection using UFW firewall and Fail2ban
• Daily health monitoring for services, ports, and certificates
• Admin control panel and API for managing users and aliases

The architecture relies on a curated set of existing tools, including Nginx for serving autoconfig settings and Munin for system monitoring. It uses Duplicity for managing backups and z-push for Exchange ActiveSync support. The system is designed to be idempotent and auditable, meaning the configuration is applied consistently across the installation. It is intended for users who prefer a pre-defined, working configuration over a highly customizable system, as it explicitly avoids providing user-configurable setup options during the initial deployment to ensure the server just works.

This software serves as a complete, self-hosted communication solution for users seeking decentralization and privacy through the ownership of their own mail server.