Reinstalling Mac Mail

How do I go about reinstalling Mac Mail? Mine seems to be playing up - I've got scrambled text and I've lost the little red icon that appears in the dock saying how many new messages are in the inbox. I have my Mac Pro installation CDs but I sure don't want to do a complete reinstall.
Any other suggestions to make Mac Mail behave?
thanks

Download Pacifist. Just what you need!
http://www.charlessoft.com/

well I certainly need some kind of pacifying.

Just found the answer myself, if anybody else gets the same problem: It was a font issue. I had disabled a bunch of fonts in Font Book in order to work on one particular graphics project. When I re-enabled all the fonts the problem with Mail was resolved.