OSX Mail - Setting root mail folder

I'm trying to set up Mail 1.3.11 (under OS 10.3.9). My e-mail account provider tells me I may need to set my root mail folder to "mail/" so that the mail client doesn't show other system files in the home directory.

Sure enough I do need to do this (I can see several system folders in addition to a folder entitled "mail" that contains all my emails. How do I set my root mail folder?????

Thanks for the help!

What kind of account are you trying to set up exactly? Who is your provider?
What he is asking you to do doesn't really make much sense (to me at least) as email clients don't enable external access to the files on your drive, they only enable you to either retrieve mails from your providers servers - or they let you access your providers servers to read, edit and sort your mail there.
The location of your mail folder should be irrelevant.