Our version 4 supports Microsoft Outlook 2010 for both web add-in as the Outlook plugin. Are you still using an older version? In that case you can use Version 3 of our add-in to sent secure mail.
Supported Windows version: Windows 7, Windows 8, Windows 10
Supported Office version: Office 2010, Office 2013, Office 2016, Office 365 and Office 2019
Supported .NET Framework: Our installer checks for version 4.7.2 and up.