Pinned messages ("Classic Messenger" interface mode)
You can mark incoming message as pinned that means that the message will be automatically displayed on the Today's Messages tab every next time when you start the messenger. This is useful when you want to do not forget on important messages and notifications that you received.
To pin a received message switch to the Today's Messages tab in the main window, then click Pin button on the message toolbar or select "Message\Pin" from the main menu.
To remove message from your pinned list, deselect the same menu item or press again Pin button on the message toolbar.