How to autocomplete with LDAP directory in Mail.app? Is it possible to have Mail pull matches from an LDAP directory as I type them in the To/Cc/Bcc fields?
I was able to get this working by adding a new account in Contacts.app.


Contacts > Add Account... > Other contacts account... Countinue
Change CardDAV to LDAP and enter the Server Address


After doing this, Mail began to autocomplete addresses.