Incoming Emails – Sharepoint 2003

I am working for a portal developed in SharePoint 2003 and for some reasons we shall not be able to migrate the same to MOSS 2007. So I need to implement this requirement with SharePoint 2003 itself. I found an option in SPS 2003 (Email Enabled Document Libraries) which uses the Public folder option to port the incoming emails to SharePoint 2003 Document Library.

It will be of great help if you can throw some light on the configuration options(if any) which is available in SPS 2003 which doesn’t use the Public Folders to port the emails to SPS 2003 Document Library.
Thanks & Regards
K. Rangarajan