Occasionally, we may send emails to your registered email address in order to provide updates and/or to notify you of new activity that is pertinent to you. You can customise the frequency of the community digest (including disabling it outright), as well as select which types of notifications to receive via email, via your user settings page. Unless explicitly changed in your user settings.
If you mean this, it's referring to emails about the forum etc. And how you receive notifications. Nothing more