Original Title: The look of the body of an email

I'm using Windows 7 and Windows Live Mail. When I receive an email, it looks fine. The sentences will continue on the next line when the email reaches the edge of the screen. When I reply, frequently the sentence will continue in one straight line until I hit return to go to the next paragraph. How do I get my sentence to fit the screen and continue on the next line? I can scroll to see it, but it is not all on one screen.

Thank you.