postfix + cyrus-sasl + ldap 配置问题！！！急！！！

sunfeng116

sasl ：/usr/lib/sasl2/smtpd.conf
pwcheck_method: saslauthd
log_level:3
mech_list: plain login

/etc/saslauthd.conf:
ldap_servers: ldap://127.0.0.1
ldap_search_base: o=Computers,dc=testdomain,dc=local
ldap_filter: (&(objectClass=JammMailAccount)(mail=%u@%r)(accountActive=TRUE)(delete=FALSE))

/etc/postfix/main.cf:
smtpd_sasl_auth_enable = yes
smtpd_sasl_local_domain = $myhostname
smtpd_sasl_security_options = noanonymous
smtpd_sasl_application_name = smtpd
......

用testsaslauthd验证时出现如下错误：saslauthd[4201]: do_auth         : auth failure: [user=kurt] [service=smtp] [realm=testdomain] [mech=ldap] [reason=Unknown]
请高手解答！！！这个问题郁闷了好久了！！！！