The Preferences menu is your go-to place to change email notification settings and to update some site-wide preferences. To access your preferences, navigate to the drop down from your global thumbnail, and click on "Preferences."
From the preferences page, it is easy to control which activity you'd like to receive email notifications about. These options include whether to be emailed about activity taking place in your connections stream, notifications coming in through your inbox, or even how often you'd like to receive the new community digest, which is a recurring email that sums up all of the popular and important activity in the communities.
The Preferences page is also the place where you can update certain site preferences like your time zone, language, and a new feature called quick tagging mode, which allows you to update tags on your content without clicking "edit."