Sometimes, I'll see a thread that indicates there are new messages. But it's a thread that I'm not really interested in, so I don't read it. The next day, I happen to notice that the thread is now marked "no new messages".
Is there something that automatically marks all messages as read every so many hours?
Or does "new messages" mean new="unread, but posted in the past 24 hrs," rather than new="unread"?