Netscape ?/Mail/Inbox?number=0 to specify an Inbox file. If the boot volume name has been changed, any unscrupulous webmaster would not know how to specify this path."
Update: Jud Spencer of Claris writes: "Emailer 2.0 is not vulnerable to this. Emailer 2.0 stores its mail in a database not individual text files. Emailer 1.0 stores individual mail messages as text files but it does not store them at any easily guessed pathname."