I put this on the back burner and finally got around to figuring this out. For those of you who want to configure LDAP on Ricoh MFPs, I've attached some documentation.
If you have a good understanding of LDAP you will probably be like "duh"! If you're just a copier guy who is trying to fake it until you make it like me, you might find this helpful. I used these settings to set up LDAP with my 2003 Small Business Server and Exchange...just to prove it can be done with our equipment in case the competition says theirs can.
Now I'd like to see how I can get the MFP to automatically update user's sent bins when sending emails so they have an audit trail.
Anyway, here's the documentation if it helps anyone.