Mail pane is different

My workstation was just upgraded from client v5 to v6.5. I do not like the way that the left folder pane in the MAIL view is different. I want the old view back where I could see all of my folders left justified with little arrows indicating which folder was open. The new view acts like windows explored and keeps opening up new levels of folders that keep shifting to the right causing me to not be able to read the whole name of the folder. The font is also larger. How can I get the old look back? (Let me know if you don’t understand my question). Thanks.