Kanbanize allows you to subscribe only for the notifications that you are interested in and by that avoid the hundreds of notification emails that eventually turn into spam.
To subscribe for the notifications that you want to get, go to Notifications and click settings.
On the settings panel you can choose between system notifications (the left column with check boxes) and email notifications (the right column with check boxes). All these are per board, so make sure to select the board that you are interested in.
Email notifications arrive into your inbox as soon as the action happens and the system notifications look like that: