Alternativas ao GyazMail para F-Droid com licença de código aberto

• F-Droid
  Todas as plataformas Windows Mac Linux Chrome OS Android iPhone Apple Watch Android Wear iPad Android Tablet Windows S Web Self-Hosted BSD Xfce Haiku PortableApps.com Slack F-Droid Ruby Gmail GNOME Cloudron Amazon Echo (Alexa Voice Service) OpenPGP PureOS (Purism) S/MIME
• Licença Open Source
  Qualquer licença Licença gratuita Licença Open Source Licença comercial