Mox is a modern, full-featured open-source mail server written in Go, for those who want to self-host their email with little maintenance. A single program handles SMTP for sending and receiving messages, IMAP4 for mail clients, webmail, and an account and administration web page. Mox sets up authentication with SPF, DKIM and DMARC, obtains TLS certificates automatically through ACME, and supports MTA-STS, DANE and TLSRPT, among others. Spam filtering uses a per-user Bayesian filter and sender reputation tracking. Mox is installed as a binary, preferably on a dedicated machine running a Unix operating system, and comes with a quickstart command that generates the configuration and the required DNS records.
Mox is licensed under the MIT licence and is developed and maintained by Mechiel Lukkien; no company controls the project. The work has been funded through NLnet and the European Commission's Next Generation Internet programme. Because you run Mox yourself, you decide where mail and account data are stored, for example in a data centre in the EU. Operations and security of the server remain your own responsibility.