Hello,
This is a common report in our Community. The problem is in the quick access panel private message notifications hard to recognize without opening the messages. It mostly an issue if the title is same for example when users send pm from a topic. This way first time the notification can easily recognize because the sender name is there but when the recipient reply this message the notification will show the last poster name which make all pm notifications looks same. Same name, same title. Is that possible to show the participants name in this notification? Only show a few participants name if there are more just to make the notification easier to recognize. 
Thanks