You can also do this for any of your other NeXT preference files that you want to keep private. If you use NeXTMail, you need to modify your Mailboxes directory to point to your home directory. NeXT's file browser provides an excellent way to see if you setup your account properly. Then see what any user does and does not have access to. In general, most of your stuff goes in home.
NeXT stuff is the exception.
And elm needs to be tweaked. Here's an overview of what the account setup looks like. You might not have all the files listed. You may have more. I find it easiest to create a group using pts and add my friends to this group.