The "Low Energy Server" at a glance:
Available Operating Systems
All 32bit Linux, preferrable without graphical interface,
The graphical interface is consumes too many resources Windows
Mail-Server, Firewall, Router, optional HDD or SSD, possible SD-card, onboard GBit NIC (2 GBit NIC or WLAN card can be tetrofitted).
CPU & RAM
To start the Intel Atom Z500 series with 1GB RAM is provided, expansion to other CPU/RAM variations is already in the plans.