I had integrated ldap with postfix in rhel 5 operating system.
But when i try to send mail to user which i mentioned in ldap database.
i got the below error. 

Jun 27 00:02:42 master postfix/pickup[3753]: C4FC51FB85: uid=0 from=<root>
Jun 27 00:02:42 master postfix/cleanup[3831]: C4FC51FB85: message-id=<20080626183242.C4FC51FB85@master.panafnet.com>
Jun 27 00:02:42 master postfix/qmgr[3754]: C4FC51FB85: from=<root@panafnet.com>, size=326, nrcpt=1 (queue active)
Jun 27 00:02:42 master postfix/local[3760]: warning: dict_ldap_lookup: ldapaliases: Search base '' not found: 32: No such object
Jun 27 00:02:42 master postfix/local[3760]: C4FC51FB85: to=<rambo@panafnet.com>, orig_to=<rambo>, relay=local, delay=0.22, delays=0.19/0/0/0.03, dsn=4.3.0, status=deferred (alias database unavailable)