Did you know that you can set your mail to preview more than two lines? The iPhone has this option, too, but its smaller screen means that it's not so practical. On the iPad, however, I find the feature is pretty handy for skimming several emails without opening them.
Go to Settings -> Mail, Contacts and Calendars and select "5 lines" under Preview. Also, while you're at it, you might want to update your Push email from "Manual" if you like to have your messages waiting when you open the Mail app. Of course, this will drain power a bit more quickly.
"iPad Tips and Tricks: Preview More Of Your Mail "
Reference : top-ipad-video-converter.com