By scrolling down in Dashboard Preferences, your customers can set the preferences for the Notification.  Customers can set the ‘Notification Preferences’ of modules. They can tick the module for Create & Status Change
Create: If you perform any actions, the customers will get the notification if they are in that User Group. g. if new meeting is created by you, the customer will get notification related to the meeting.
Status Change: If Status is changed by you, they will get notification.
By clicking on the Notification ‘icon’, the customers will get the notification with the highlighted details as shown above image. 
By clicking on the View All option, the customers can see all the notification in detail. 
The ‘Delete’ option is also given if the portal user want to delete any notification. You can also delete the unwanted notification from the list. Select notifications and click on “Delete” button or click on “Delete All” button if you want to clear the notification list. 
You can also apply filtering on notifications for various parameters as mentioned below: 
Type: Notifications are generated on basically three type i.e. on create, on status change and on case updates. So, you can apply filter and view specific type of notification list.
Module: Choose module to view module-specific notifications.
Start Date and End Date: Choose dates to view in between notifications for that particular day, week, month or year.