"Chicago is it's own incredible theater town right there smack down in the middle of the heartland. What a great city! I can see why Oprah likes to live there!" - Dee Hoty :-D
ANYHOO....to answer poor Deena's question. This is how Rob (the webmaster) described the envelopes:
These will show if there's been new messages posted in a thread since you've viewed it (open envelope) or if not (closed envelope). Also, the subject lines will now rebold themselves if new messages have been posted as well...
Additionally - you'll see a red version of the two icons, which signifies a 'Hot Topic,' currently defined as a thread with 500+ views and/or 30+ replies. I might tweak that number higher, we'll see how it goes.
He also cautions:
The envelopes work via cookies... So if you've got them turned off in your browser for one reason or another, they won't change from open to closed. You may also need to refresh to see them based on how your browser is set up.
The threads changing from bold to regular is cookie independent so should work regardless of your browser settings.
"Do you know ChrisLovesShows?" "Yes. Why, yes he does!"
Sorry I didn't answer the question--to be honest, I wasn't sure how they work myself. I don't pay the envelopes any attention if I want to read or reread something I just do.
I don't get the whole envelope icon thing. Just ignore them. I log in and there's a closed envelope but no new post, an open envelope but I've nevre looked at the thread before, open envelopes on threads I have read but there may or may not be a new post. I liked it better when a new post caused the thread to be bold and moved up.