Alternativ till Mailsac för Gmail med gratis licens

• Gmail
  Alla plattformar Windows Mac Linux Chrome OS Android iPhone Windows Phone iPad Android Tablet Web Self-Hosted Software as a Service (SaaS) Firefox Opera Safari Windows Mobile Xfce Apple TV Chrome Gmail Telegram Yandex.Browser Viber
• Gratis licens
  Eventuell licens Gratis licens Open Source-licens Kommersiell licens