How to hide messages that have already been dealt with?

If you hover the mouse over the message, four icons appear. Press the tick icon to mark the message as done.

The message will be then hidden from the list of messages.

If you wish to display all messages i.e. including the "done" messages, click on the "Show done" button.

Messages already dealt with can be hidden in the mobile application in a similar way. How to delete a "done" message from the list of messages in the mobile application