listmonk

listmonk is a free, open-source newsletter manager designed for self-hosting. It's a single Go binary that deploys easily and comes with a built-in web interface for managing subscribers and campaigns. Since you run it yourself, there are no per-subscriber fees, no per-email charges, and you own all your subscriber data entirely.

This appeals to developers and privacy-conscious publishers who want complete control over their infrastructure. If you have the technical chops to run a server but want to avoid platform lock-in and escalating monthly costs, listmonk delivers a lean, reliable alternative. SQL-based segmentation and automation help teams scale newsletter operations without paying per contact.