OpenEMM

OpenEMM is an open-source email marketing suite with enterprise-strength features for audience targeting and campaign orchestration. Originally developed in Germany, it's been free to self-host for years, offering segmentation, A/B testing, and automation workflows without paying per contact. The platform includes tools for form building and analytics that typically come with premium price tags elsewhere.

It suits marketing teams and agencies managing complex campaigns across large lists. If you need features typically locked behind expensive SaaS tiers, dynamic content, trigger-based sends, detailed analytics, OpenEMM brings that power to a self-hosted deployment.