Mac notifications

I am using Brosix on a Mac computer. If I am not at the computer and someone sends me a message a notification is shown and then disappears. How can I know I have received a message when I get back after the notification has been closed?

When you receive a text message, Brosix places a red circle on its doc icon.

Brosix Mac Doc notification
You can also configure Brosix to show a sticky notification for the missed messages and events. To enable sticky notifications, go to menu Brosix – Settings – Notifications.

Sticky notification