If a MAPI-enabled e-mail client is installed, MAPI is added to the host
and that includes a "Mail" named applet in Control Panel. If you don't
see an applet named "Mail" in Control Panel, maybe you don't have
Outlook properly installed or you perform a migrate that didn't
complete. Also see
http://support.microsoft.com/kb/937763.
If you're using Vista, you'll have to figure out how to configure the
Control Panel display to get rid of the Fisher-Price kiddie fluff
display to eliminate the categorization of configuration settings. I
have done it in Vista but don't use it often enough to remember how to
get rid of that fluff crap in Control Panel. As I recall, under Vista,
there is the "View 32-bit control panel items" category if you are using
a 64-bit version of Window Vista. You didn't mention WHICH version of
*Windows* that you use so you'll have to dig around to find where the
Mail applet got hidden in Vista.
So back to my prior question, did you ever define e-mail accounts for
Outlook to use? Your original post implies that Outlook was working
with one, or more, e-mail accounts and then stopped but that's an
implication as you don't actually say that you were successfully *using*
Outlook before.