Choosing a Mobile Device Management (MDM) (opensource or free) service for a closed system?

Question

Mobile development

You need to select Mobile Device Management (MDM) service for a closed system (without access to the Internet and google services) (your own vpn 3g network), an opensource or free solution. End devices on Android, the server is possible on Linux and Windows Server 2016. Already installed and tested Flyve MDM and WSO2 IOT, the first one would be perfect if not one but - you need a deployed mail system on the network with this system (user login data comes there through a mobile agent), the second one has too many bells and whistles and did not start on a not very powerful vds server (2CPU and 6 GB of memory). The possibility of mass deployment of applications on android devices is needed (almost all are of the same type - Lenovo tablets). Maybe someone knows a good opensource or free MDM solution for these needs, provided that

Answer 1

I would be happy to recommend the open source MDM system Headwind MDM: https://h-mdm.com Compared to Flyve MDM and WSO2, it is very easy and quick to install, it can work without access to the Internet.
The only thing is that there is no built-in mail system, since it is still a system for automatically deploying mobile applications, and not a universal solution for "everything". But, as far as I know, there is no built-in mail system in any MDM system - they are not for this. In theory, it is not difficult to deploy a mail server on a local network.