I just received my 2011 2.7ghz iMac yesterday and the Mac Mail app keeps shutting down. You don't even have to be checking out emails are anything. You can just open the application, it searches for new emails and retreives them, and then shuts down after being open for about 20 seconds. I have tried a few things. First, I checked for software updates; none. Then I deleted the com.apple.whatever file from preferences and then setup my email account again and that didn't help. I then called Apple and that guy walked me through a few things like setting up another user account to see if it would do the same thing logged on as someone else; it did. So then he told me to reinstall the OS. I just did and it is still doing it. I tried to call Apple back, but now they are closed. Do any of you have any idea what could be causing this? I use the same gmail account on my iPhone and Macbook Pro through Mac Mail and those work just fine.