Browse to Admin, Login, User registration and login
Browse to Admin, Login, PEAR::Auth
Done!
Customizations required for IMAPS/SSL Support highlighted in green below.
Click "Change preferences" at the bottom of the section
Documentation needed.
Copy/paste from mailing list: "On your page, in authentication, you are missing IMAP(S), it is a very good and simpler way to authenticate than LDAP. I just implemented it. It uses the same PEAR:Auth library."