Outlook Express 6.0 does not delete messages from dbx files, even when a user empties the Deleted items folder, which allows local users to read other users email.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2002-2181
http://www.ntbugtraq.com/default.asp?pid=36&sid=1&A2=ind0210&L=ntbugtraq&F=P&S=&P=5732