LDAP is a protocol that provides access to directories of information. LDAP directories are composed of entries that are organized into hierarchies. You have to understand how LDAP works and how your own directory is organized to use it with Postfix. Many networks are starting to make use of LDAP for user information, which makes it a nice way for Postfix to determine what users and addresses it should accept mail for. If your organization uses an LDAP directory, you can query your existing information for your Postfix configuration.
LDAP maps are specified with the
ldap map type and can be listed along with
any other maps for a given parameter. Unlike MySQL, LDAP parameters are all listed in main.cf. You have to invent a name for the
particular LDAP configuration you are creating and specify it with the
ldap map type. If you call your
example, set your alias maps like this:
alias_maps = ldap:ldapaliases
The LDAP parameters for this configuration all start with the
name you invented followed by the name of the parameter. Thus, the
LDAP server is identified by the parameter
_server_host, so for the example above, the
parameter is called
ldapaliases_server_host = ldap.example.com
The important LDAP parameters are defined below. The complete list is available in the LDAP_README file that comes with the Postfix distribution:
The base DN from which to start the search. You have to know ...