I see subscribe archives, but not understand RC support email threads or not? I use $rcmail_config['autoexpand_threads'] = 1 but nothing happens.
"Threaded message listing" in main RC page that mean?
You've got to choose threaded view for any given folder. Either under "Manage Folders" or in viewing the message list of that mailbox, click the cute litle icon that looks like a settings dialog dropping down, which it does ;) next to the Subject column header.