Installation of the Microsoft .Net Framework 4
Since the 3.11 release, this framework is needed on machines where you want to run PYTHEAS MailGate. If you received a corresponding warning message, and you have been directed to this page, it is probably not yet installed.
How to install the Framework on Windows Server 2003 / 2008 / 2008R2
On Windows Server 2012 / 2012R2 / 2016
The framework (or a later version) is installed by default.