Email preferences can be adjusted by signing in to your account, then clicking on Profile > My Account > Email Preferences. You'll be able to choose which types of emails you receive, and opt in or out of email categories as you wish. Please note that community updates, newsletters, and other opportunities will always be sent as a "Community Email".
You can choose additional email settings under Profile > My Account > Community Notifications. There, you'll be able to choose daily or weekly digest of all discussion posts, as well as when they're delivered.