I have several Mac laptops, RMB, MBA, MBP all with current OS and apps, but the MAIL app on my RMB does crazy things -- sends and receives duplicates of each email, places email I sent into the Draft folder, and other wacky things. I spent 45 minutes on the phone with applecare, erasing every remnant of the app, starting all over again, and it's doing it all again. Apple claimed there's noting wrong with the app. And I use the same MAIL app on my other macs and have never had a problem. Since I use email everyday for business etc it's truly annoying.