To pep up your mail, you can, if you wish, you can have a background image, as stationery in your Windows Live Mail.
To do so, open Windows Live Mail > New Message > Format > Apply Stationery > Select Stationery.
Make sure that you have checked the Rich (HTML) formatting option checked.
If you have downloaded and saved stationery in other locations, you can also select More Stationery from these locations.
Do note that Windows Live Mail 2011 does not support this.