Ldap Service Crashes Frequently

[prasadpimple]

Oct 17 05:04:05 jhpsecurities postfix/smtpd[5986]: Anonymous TLS connection established from localhost.localdomain[127.0.0.1]: TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)
Oct 17 05:04:05 jhpsecurities sendmail[11791]: STARTTLS=client, relay=[127.0.0.1], version=TLSv1/SSLv3, verify=FAIL, cipher=DHE-RSA-AES256-SHA, bits=256/256
Oct 17 05:04:11 jhpsecurities postfix/proxymap[12309]: error: dict_ldap_connect: Unable to set STARTTLS: -1: Can't contact LDAP server
Oct 17 05:04:11 jhpsecurities last message repeated 2 times
Oct 17 05:04:11 jhpsecurities postfix/trivial-rewrite[12308]: fatal: proxy:ldap:/opt/zimbra/conf/ldap-vad.cf(0,lock|fold_fix): table lookup problem
Oct 17 05:04:11 jhpsecurities postfix/proxymap[12309]: error: dict_ldap_connect: Unable to set STARTTLS: -1: Can't contact LDAP server
Oct 17 05:04:11 jhpsecurities last message repeated 2 times
Oct 17 05:04:11 jhpsecurities postfix/trivial-rewrite[12310]: fatal: proxy:ldap:/opt/zimbra/conf/ldap-vad.cf(0,lock|fold_fix): table lookup problem
Oct 17 05:04:11 jhpsecurities postfix/proxymap[12309]: error: dict_ldap_connect: Unable to set STARTTLS: -1: Can't contact LDAP server
Oct 17 05:04:11 jhpsecurities last message repeated 2 times
Oct 17 05:04:11 jhpsecurities postfix/trivial-rewrite[12311]: fatal: proxy:ldap:/opt/zimbra/conf/ldap-vad.cf(0,lock|fold_fix): table lookup problem
Oct 17 05:04:11 jhpsecurities postfix/proxymap[12309]: error: dict_ldap_connect: Unable to set STARTTLS: -1: Can't contact LDAP server