Mavericks has been a complete waste of my time. It's one problem after another. This is the worst Apple upgrade I've ever done. I've had problems with upgrades in the past, but the issues tended to be isolated to a few specific things and were predictable once I figured out what was hanging. Every day I find something else that's not working right. Now it's more mail problems. It won't recognize any new rules that I setup. Also, it's suddenly extremely slow when autocompleting email address when I use OSX Mail. It also suddenly doesn't remember a lot of email addresses too. To make matters even more fun, I tried rebooting, but it wouldn't quit any of the programs. I force quit everything, but then it refused to reboot so I had to open up terminal and run the reboot command from there. When everything came up again, I realized why it wouldn't reboot... because it didn't actually quit any of those programs I tried to quit and then force quit. It treated the reboot as a crash and proceeded to restore program states from programs that I thought I had quit out of way before. Of course this then took 20 minutes before my Macbook Pro would actually do anything but make disk drive sounds. Ugh. Nice features in Mavericks. Not worth the hassle. Not ready for prime time.