This happens to me at least once a day: I'll be sitting at the computer, and regardless of what I'm doing - typing, watching a movie, clicking around - I get the "new mail" sound, which prompts me to check Mail. But - no new mail. The sound comes on when I DO have new mail, as expected, but every now and then it happens even when there's no new mail. I have only one mail account and I can check it online as well, so I'm positive that there is indeed no new mail. Any idea what else could be making the sound? I've looked and thought and clicked, but it seems to happen regardless of what apps I have running or what I'm doing at the time.