In Windows-based networks LDAP = Active Directory. (or if you have a very old mail system, Exchange 5.5)
So to stop LDAP from listening, the system must have the domain controller role removed.
PSC
Governments and corporations need people like you and me. We are samurai. The keyboard cowboys. And all those other people out there who have no idea what's going on are the cattle. Mooo! --Mr. The Plague, from the movie "Hackers