Little Useful Feature in Outlook: "You Are Not Responding to the Latest Message in This Conversation"

As annoying as Outlook is most of the time, it has a few nifty features. For example, this notification:

appears at the top of a compose window when appropriate. It is very useful because it appears if, while you are typing a message, another one comes into the same thread, thus reducing occurrences of “crossed” (and possibly conflicting) responses.