So lately, and this doesn't happen constantly, but the email app will refresh (inside the app while I'm watching) and download a new message. In the left pane the preview pops up for like a second, then disappears before i can even click. Then it says under the list of previewed messages for example...4 messages, 1 unread. If I hit refresh again it will pop back up then go away. After a couple of tries it comes through fine, but it's really obnoxious. I only recently started having this problem, and haven't messed with any settings or any new programs since I got here to Germany 5 weeks ago.
I'm using GMail.