Every Admin by default, is set to receive all notifications via email. 

To disable this feature, just go to the Admin whom you wish to turn off the notification emails for. 

Under Admin profile, select Edit email settings 

On this screen, unpick the emails notifications to disable them for that Admin User. 

Then select Save changes 

This will now stop emails regarding digest and viewing requests coming to this users email address, 

Just re-pick the emails and save if you want to re-enable these email notifications.