Outlook 2007 Resizes My E-mail Text - How Do I Turn This Off???

I have my Outlook 2007 Stationary set at Calibri 12 pt font for all types of
e-mails (new, replies, forwards, reading, everything). When I open a sent
e-mail or compose a new one, the font is just fine - 12 pt, large and
readible. However, whenever I reply or forward a message, Outlook resizes
the e-mail to make the text smaller. Understand, Outlook isn't making the
text 11 or 10 pt, it's resizing the entire message to make everything
smaller. I know it's still 12 pt because my e-mail system at work defaults
to have replies be "plain text" (which I'd also like to fix...) so when I
change the e-mail to Rich Text or HTML and check the font size it's still 12
I know this seems minor, but it's driving me crazy. I set my e-mail at 12
pt so that I can read it. When it resizes to the equivalent of 10 pt, it
makes it harder to post my response or re-read the previous e-mail.