Outlook 2003 Paragraph Spacing is Auto

How can I set the DEFAULT paragraph spacing (Indents and Spacing) to be a value of 0 instead of Auto (Before and After) which inserts an additional line between paragraphs when hitting the “Enter” key?
I have to set it manually each time I create a new msg or reply. I am using MS Word 2003 as my Outlook editor. There are no Options for this available in Outlook or Word.