Go to your initials in the top right-hand corner and from the user menu choose “Preferences” and then “Notification Preferences”. Here you can change your general preferences for receiving notifications within POK or by e-mail.

Please note that these preferences apply on a general level: in order to actually receive notifications from a specific content, they must be activated for that content. For example, in order to receive notification of a new post in a forum, you must "subscribe" to the forum or thread (read the FAQ I don't get forum notifications, how do I activate them?).