I have a running zimbra server, and would like to make another sever authenticate against ldap. It is apache using mod_authz_ldap

here is my .htaccess file. It pops up and asks me for my login info, but I cannot seem to log in no matter what i do. I suspect i'm not configuring this correctly.
I am especially unsure about my use of AuthzLDAPRoleAttributeName.

AuthzLDAPEngine on

AuthzLDAPServer zimbra.mydomain.com
AuthzLDAPUserBase dc=mydomain,dc=com
AuthzLDAPUserKey uid
AuthzLDAPUserScope base
AuthzLDAPRoleAttributeName mail

AuthType basic
AuthName "Login Required"
require valid-user
And I suppose the next question would be, do I have to use a BindDN to authenticate. I know thunderbird doesn't need it for the address book.