Problem: When someone gets a message while being afk, its very likely that this message is lost forever.
Not everyone knows about the hidden system message window.
Solution: Add the message to the messenger window. And a little post icon on the screen that disappears when the messenger is opened.
This way i can also see -> when <- i got messaged and if it makes sense to answer (getting invited like to dungeons).
good suggestion, also i want to add being able to minimize chat windows instead of just closing them and reopening them would be great