If you type a full user name in the Display Name field in the Find dialog box of your address book when you try to search a Lightweight Directory Access Protocol (LDAP) server in Outlook 2002/2003, you may receive the following error messages:
Unable to display results because too many entries in the Internet Directory match your search criteria.
The search could not be completed. MAPI_E_CALL_FAILED.
Cannot contact the LDAP server (81) error.
Please find the following Support kb which gives resolution for Outlook 2002 and Outlook 2003.