Alternatívy programu Posteo pre S/MIME s komerčnou licenciou

• S/MIME
  Všetky platformy Windows Mac Linux Chrome OS Android iPhone Apple Watch Android Wear iPad Android Tablet Kindle Fire Windows S Web Self-Hosted Software as a Service (SaaS) Windows Mobile Java Mobile F-Droid S60 Android TV Chrome MetaMask Gmail Amazon Appstore OpenPGP S/MIME DAVdroid
• Obchodná licencia
  Akákoľvek licencia Bezplatná licencia Licencia Open Source Obchodná licencia