Please note that there are two ways to disable IPv6: through the Control Panel and through the Registry Editor. Using the Control Panel method will only set your system to prefer IPv4 over IPv6, but not disable IPv6 fully. 
 If you want to fully disable IPv6  and understand the risks to your Windows components if you do so , please see the Microsoft article at the bottom of...
                           
                           
                               Article Id:
                                17573
                               
                           
                           
                               Category: Office365 & LSUMail