Mox is a modern full-featured open source secure mail server for low-maintenance self-hosted email.
Mox addresses the complexity of running your own mail infrastructure by providing an integrated solution that handles SMTP, IMAP, and webmail in a single binary. It implements modern email security standards including SPF, DKIM, DMARC, DANE, and MTA-STS with automatic TLS provisioning via ACME. The server includes built-in spam filtering with Bayesian learning and reputation tracking per user, along with a web admin interface that guides domain setup and DNS configuration. A quickstart command generates initial configuration, and the tool can run locally for testing via a dedicated subcommand.
Mox suits operators who want to self-host email for their own domain without managing multiple separate services or dealing with complex configuration. It works well for small to medium deployments where simplicity and security matter more than handling massive scale. The project includes a webserver component that can serve static files and act as a reverse proxy, allowing port 443 to double for website hosting. The HTTP API and webhooks enable integration with transactional email workflows. Interoperability has been manually verified against major email clients and cloud providers including Gmail, Outlook, and Proton Mail.
Almost all open issues are raised by outside users rather than by the core team, indicating a substantial base of adopters reporting real-world use. Maintainers typically respond to new issues and pull requests within a day.
