Alternativy k NeutronMail pro S/MIME s licencí open source

• S/MIME
  Všechny platformy Windows Mac Linux Android iPhone Android Wear iPad Web Self-Hosted Software as a Service (SaaS) PHP JavaScript Windows Mobile Java Mobile S60 Docker Cloudron OpenPGP Kubernetes S/MIME OpenShift DAVdroid
• Licence Open Source
  Jakákoli licence Bezplatná licence Licence Open Source Komerční licence