I don't really know what happened. My guess is that it has something to do with the .plist file com.apple.mail.plist. I have verified this on 10.5.2 and 10.5.3. If you use mac mail and have at least three accounts to 5 accounts of any variety, try it out. Open about 15 message windows and then check mail. See if you can get your pop or other server to fail on checking your password. Guess what the fix is, that's right! Use Flags and not open messages to mark what emails you need to respond to. Then, create a smart folder that shows only flagged messages and you too can leave your inbox empty!