How do I change the right hand margin on my email letters?

My husband has been using my computer a lot recently and he knows very little about them (I only know a little more). I have now found that when I receive emails and want to print them out they overrun the right hand margin so I miss off a couple of letters. I always use Outlook Express for my emails. Please can anyone tell me how I can change this.
How do I change the right hand margin on my email letters?
On the print dialog box. click on the preference button. Go to the effect tab and check if the % of normal size is set to 100. Hope this helps you.
Reply:Open the mail you want to print. Click on print. When that comes up click on preferences. Set the paper size to the one you use.