So, this is a weird one... I've searched around and can't find anything that comes close to this. I have a 15" MBP that is connected to a ViewSonic external monitor. Everything worked fine, life was good. I just got a new 15" MBP (newer model) and moved my data over to an SSD that I put in the new MBP. Everything is working just fine. The weird thing is that, when I disconnect my external monitor and have my Mail app open, my mac makes a repeated ding sound and then repeats the swooshing mail sound (when you send an email) over and over again. It doesn't cause the beach ball or the Mac to lock up. It just makes those sounds. Sometimes it repeats alot, sometimes just a couple of times. When the Mail app is closed and I disconnect, it doesn't make the sound. It's so strange because it's just the hardware that's changed and it never did this on my old MBP. Anyone ever heard of anything like this before?