Have been using T-Mobile version of this device for over a month. Installed the latest available version of K-9 Mail (ver 4.409, Dec 17, 2013). It downloads emails when a gmail account is first added, but after that the Inbox always shows EOFException and does not download any more emails. Tried with a couple of gmail accounts that work fine with older version of K-9 Mail on an older Android phone. Tried on both wifi and TMobile 4G networks. Tried both Push and Polling. Push gets into a unending cycle and drains battery, data-usage. Has anyone else tried using K-9 Mail on this device?