'gdif,' who posted the Airport base station emulator page, has put together a little how-to on enabling 'sendmail' in OS X v10.0. You can find the article here:
http://homepage.mac.com/gdif/tipstricks.html
In addition, there are some other great UNIX tips on that page, including a "renice" command for the Window Manager that may potentially speed up your window redraw. I've added the site to the links section as well.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20010328080329748