Outlook 2000 and 2002 provide support for
Lightweight Directory Access Protocol (LDAP) queries, which enable
Outlook users to look up contacts stored in an LDAP server such as
the Windows Server Active Directory. However, successfully querying
an LDAP server requires a user to properly configure the server’s
settings and set the search base for the query.


To set the search base for an existing LDAP service in Outlook
2000, open the Mail applet in Control Panel, select Microsoft LDAP
Directory, and click Properties. Enter the appropriate search base
string in the Search Base field at the bottom of the General

To set the search base for an existing LDAP
service in Outlook 2002, open the Mail applet in Control Panel,
click E-mail Accounts, select View Or Change Existing Directories
Or Address Book, and click Next. Select the LDAP service, click
Change, and click More Settings. Select the Search tab, and enter
the appropriate search base string.

Search base

The search base defines the starting point for the search in the
directory tree. For example, a user might need to query the entire
directory, in which case the search base must specify the root of
the directory service. Or, a user might need to query a specific
organizational unit (OU) in the directory.

this case, you might configure multiple LDAP service accounts in a
user’s profile to enable him or her to look up contacts for the
Support, Sales, and Marketing groups separately. Each of these
queries would need to have the search base point to the appropriate
location in the directory service.

A search base comprises multiple objects
separated by commas. These objects include:

  • cn: common name
  • ou: organizational unit
  • o: organization
  • c: country
  • dc: domain

For example, to search the Support container in
the TechRepublic.com domain, you would specify a search base


The capability to use different search base
strings to configure multiple LDAP accounts in a single profile
enables users to easily search more than one LDAP server. Although
users could change the search base for a single LDAP service
account as needed, adding multiple services with different search
bases eliminates the need for users to change settings.