When you log into Case Status you can see an Inbox option in the top right. This is where you will be able to see any messages from cases that you are associated with.
Please Note: You can only see messages where you are on the case from the inbox. Messages on cases you are not on will not show in your inbox.
How to see messages
Form your home screen choose Inbox from the top right
You can click into the message/case from this dropdown.
If you review you can Mark all as read from the top right
Choose See all messages at the bottom to get a bigger view where you can filter the messages.