InboxViewController

The InboxViewController gets its data from the DataHandler in form of a Folder object. Updates to the records are received via the NotificationCenter:

NotificationCenter.default.addObserver(forName: Notification.Name.NSManagedObjectContextDidSave, object: nil, queue: nil, using: {
            [weak self] _ in
            self?.tableView.reloadData()
        })

It provides links to the displayed mails, all mails of a contact, the ContactView of a contact, and the ContactView of the user.