Bind with attribute + RDN instead of DN

Hi All,

I want third party applications to authenticate against my ldap using any attribute (specially mail & password) is it possible to do a bind using any attribute with/without RDN rather then DN? For example my LDAP user looks like this :

dn: uid=1,ou=users,dc=example,dc=local

objectClass: inetOrgPerson

objectClass: organizationalPerson

objectClass: person

objectClass: top

cn: Josh

sn: Cho

mail: joshcho@example.com

uid: 1

userPassword: joshcho

I can bind to ldap if I use DN & password but I can not bind to ldap if I use any attribute like

mail=joshcho@example.com,ou=users,dc=example,dc,local & password

Would greatly appreciate any help.

Thanks *simon*