To change your email settings, go to the menu under your name and select "Notifications":
You will see the following options available for you to change.
To stop all emails choose each of the three menu items indicated with an arrow above and change your selection to "Do not email this type of notification"
You can also choose to change the frequency of emails you get for "New Responses & Replies" (that is, when someone comments on a post you made or answers a question you posed) to be either one email everytime there is a new response for you or once a day in a "digest" email.
Make sure to click "Save Notification Settings" at the bottom of the screen.