Our main computer is an iMac and I have an iPad as well and access the internet via wifi. Recently, when my husband attempts to access email, the computer freezes, gets that 'rainbow spin' thing.n the other strange deal is that the computer can't be shut down by any usual means, not even the button in back. The only way to quit is to unplug. He can access the other internet programs, the only problem is email. Even stranger, I can access our email using my iPad from the wireless connection we set up from the main computer. Any ideas what is going on? None of the 'experts' we consulted have a clue. Thanks.