This turned up on Gumtree for £15, the intention is to turn it into a private mail server. Being fanless and having an SSD it's completely silent, being low power should keep it cheap to run, and with its Intel Atom D510 processor it can run a 64 bit OS while being immune to a whole host of hardware exploits that have come to light in recent years such as Spectre due to it not having speculative execution. This all seems to make it a good choice for a low volume mail server. Since buying it I've removed the optional Nvidia graphics card as I have no need for graphics on a headless server, so it just represents wasted energy. The onboard WiFi adapter also came out as it's not needed, I'm just using a wired ethernet connection.
