My inbox normally is divided in half, the top half showing in messages and the lower half showing the first few words of the message. But its changed - it just shows all the email in the inbox. How can I get it back to how it was before?
I'm a little swamped with all the details you've given about what email client your using to answer fully!!
But generally click the view menu, look at reading pane options first, if that's not what you mean then look at some of the other settings on the view menu, it will be in there.