listmonk
Run your own newsletters and mailing lists from a single binary
What it is
A newsletter and mailing list server that ships as a single Go binary backed by PostgreSQL, with a web dashboard for managing subscribers, lists, templates, and campaigns. It sends bulk and transactional email over SMTP and can route messages to other channels such as SMS gateways. Organizations that want to run their own email campaigns without paying per-subscriber fees to a hosted service install it via Docker or the release binary.