3.2.2 (ii) of App Store Review Guidelines says i can't monetize built-in capabilities provided by the hardware or operating system, such as Push Notifications.
But can I sell notifications if my server does some processing (and this processing is not a built-in capability) before sending these notifications?
No. You are trying to monetise push notifications, which are built into the OS. You can certainly perform the processing on a server, but you cannot charge people to receive a push notification with the results of that processing.
What does your server return to the app? What 'product' are you trying to charge customers for?
The server performs checks for new assignments at the university and notifies about changes.
