You'd need to use VBA to do that. In old versions, you need to use CDO or Redemption (
http://www.outlookcode.com/article.aspx?id=3D31). In Outlook 2007/2010, use Inspector.WordEditor to return a Word.Document object and then use Word methods to make the changes.
Or...
Which font is used for most contacts? The font setting is in File, Options, Mail format, Stationery and Fonts - the font for New Mail messages is also used for the Notes field in all Outlook items (well, except for Notes
). Change it to the one you want to use. This won't fix existing contacts, but will make new ones use the preferred font and most items will have the same font.
I'm trying to find out if its possible to change the default +body font - you can change it in messages by changing the theme but if its possible to change the default theme, it might automatically change all usages of the default +Body style. (However, I'm not sure its possible to change the default theme. All of the other themes listed on Options tab, Themes are here: C:\Program Files\Microsoft Office\Document Themes 14 and can be edited using the same method used to edit calendar printing assistant templates.)
If it were me, I wouldn't make the effort to change all at once - I might change each contact if opened for other purposes, but i would not make a special effort to change all at once. It's just not worth the effort.