How to open EML files in Windows 8 Mail
Change the filename extension from EML to MHT, then try to open it in Internet Explorer. These extensions represent the same format.
My suggestion is NOT related to Windows Mail application at all, but in case anyone else finds this topic looking for just a tiny little program (~236 KB) for free just to view the contents of an .eml file without having to install an unnecessarily large application like myself, I would suggest using ceml:
