A few months back, I did a series of articles on The Register, in which I explained how to build your own mail server.
The system I used to do that was the Acer Revo One RL85, which I previously reviewed. The Celeron version comes with Windows 8.1., 4GB of RAM, a 1TB hard drive, and a remote control. It was listed at £199, but it’s now available from Tesco Direct for just £149. Considering you’ll get Windows 10 as an upgrade too, I think that’s a pretty decent deal, whether you want to use it as a Windows PC or for some other project – you can easily change the BIOS to boot a different OS.
If you want all the parts of the mail server piece, start with this entry
on the blog, which has links to all the parts on El Reg. If there’s interest, I may make an eBook version for download.