The following Apple Knowledge base article may help you with any email problems you experience after updating to OS X 10.6 (Snow Leopard)
Kudos to blonde_b2 for pointing it out.
Help, my PC with Windows 10 won't shut down properly
Since upgrading to Windows 10 my computer won't shut down properly. I use the menu button shutdown and the screen goes blank, but the system does not fully shut down. The only way to get it to shut down is to hold the physical power button down till it shuts down. Any suggestions?