The download has to be done in Safari! Make sure to create an application password for your device (iPhone, iPad or MacOSX computer) in the Zimbra webgui.
This application password must be used three times when the profile is enabled (for Calendar/contact sync, for receiving mails and for sending mails).

Use this file and use it with Nomachine Enterprise Client software to establish a Remote Desktop connection to the MPI/CBS. Get the client software here