https://www.openplant.org/openmta
Open MTA — OpenPlant
open mtaopenplant
https://kumomta.com/
KumoMTA - Enterprise Open-Source On-Prem/Private Cloud MTA
KumoMTA is the open-source email infrastructure for enterprises and high-volume senders who want control and continuity without the risk, volatility, or...
enterprise open sourceon premprivate cloudkumomta