If you are not comfortable with the new layout of Mail app in Mac OS X Lion then there is an option to change the Mail app layout to old Classic view.
Open Mail app in OS X Lion
Click on Mail menu and select Preferences
Select “Viewing” tab and Check the “Use classic layout” option as shown below in the screenshot
Now close the Preferences windows and see the layout is changed to Classic. You can revert back to the new Mail layout by un-checking the same “Use classic layout” option is Preferences.
Thanks trickguy for telling this option
I don’t know why people want old layouts in new versions.
not everyone likes the new view, mmkay? its not great for working with large volumes of messages.