Ok, the same happens on Windows XP Pro.
If your Outlook is setup to use Word for Windows as a default e-mail editor, it is not strange that there is WINWORD.EXE process still running. Close Outlook completely (not just minimize it, close it) and WINWORD.EXE should terminate as well.
I am still trying to find myself an answer, why WINWORD.EXE consumes so many handles? I found many tech articles how to raise the limits for available handles by modifying the registry, so I did it. Now WINWORD.EXE goes to 50 000 - 60 000 handles after only a few hours of work. At some point the XP GUI could not refresh at all - I can't open any more windows, all window toolbars disappear and I have to close whatever I can, so I could continue to work. It is true that during a normal day I have 20+ Excel, 15+ Word, 30+ IE etc. windows opened at the same time, but when I check my Task Manager I could see that all those hundreds of applications / windows consume 10-15K handles and WINWORD.EXE consumes another 50-60K.
If I find more information I will post again.