Yahoo Group Archiver is a command line utility to interact with Yahoo Groups. Currently we can download the messages(without the attachments), everything from the files section and all the images from the photo section along with their hierarchy on Yahoo
the latest consolidated grabyahoogroup.pl script works well but is currently found only by browsing the SVN repository.
The script "grabyahoogroup.pl" works well as of May 2013. Yahoo seems to put a limit of 2500 messages. Then the script waits for several hours before continuing. I'm almost done getting close to 13 thousand messages from my group. Run with nohup on a sever or desktop. The messages are stored in individual text files that are compatible with the nmh tools.