thank you and now show error :
[root@mail ~]# tail -f /var/log/dovecot.log |grep xxxx
dovecot: Jul 07 14:25:31 Info: auth(default): ldap(xxxx@myhost.net,192.6.2.85): bind search: base=ou=Users,domainName=myhost.net,o=domains,dc=myhost,dc=net filter=(mail=xxxx@myhost.net)
dovecot: Jul 07 14:25:31 Info: auth(default): ldap(xxxx@myhost.net,192.6.2.85): result: objectClass(?unknown?)= cn(?unknown?)= sn(?unknown?)= uid(?unknown?)= givenName(?unknown?)= mail(?unknown?)= accountStatus(?unknown?)= storageBaseDirectory(?unknown?)= mailMessageStore(?unknown?)= homeDirectory(?unknown?)= enabledService(?unknown?)= memberOfGroup(?unknown?)= userPassword(?unknown?)= mailQuota(?unknown?)=
dovecot: Jul 07 14:25:31 Info: auth(default): client out: OK 1 user=xxxx@myhost.net
dovecot: Jul 07 14:25:31 Info: auth(default): ldap(xxxx@myhost.net,192.6.2.85): user search: base=ou=Users,domainName=myhost.net,o=domains,dc=myhost,dc=net scope=subtree filter=(&(mail=xxxx@myhost.net)(objectClass=mailUser)(accountStatus=active)(enabledService=mail)(enabledService=imap)) fields=storageBaseDirectory,mailMessageStore,mailQuota
dovecot: Jul 07 14:25:31 Info: auth(default): ldap(xxxx@myhost.net,192.6.2.85): Unknown user
dovecot: Jul 07 14:25:31 Error: auth(default): userdb(xxxx@myhost.net,192.6.2.85): user not found from userdb ldap
dovecot: Jul 07 14:25:31 Info: imap-login: Internal login failure (auth failed, 1 attempts): user=<xxxx@myhost.net>, method=PLAIN, rip=192.6.2.85, lip=192.6.1.203, TLS
dovecot: Jul 07 14:25:31 Info: auth(default): ldap(xxxx@myhost.net,192.6.2.85): bind search: base=ou=Users,domainName=myhost.net,o=domains,dc=myhost,dc=net filter=(mail=xxxx@myhost.net)
dovecot: Jul 07 14:25:31 Info: auth(default): ldap(xxxx@myhost.net,192.6.2.85): result: objectClass(?unknown?)= cn(?unknown?)= sn(?unknown?)= uid(?unknown?)= givenName(?unknown?)= mail(?unknown?)= accountStatus(?unknown?)= storageBaseDirectory(?unknown?)= mailMessageStore(?unknown?)= homeDirectory(?unknown?)= enabledService(?unknown?)= memberOfGroup(?unknown?)= userPassword(?unknown?)= mailQuota(?unknown?)=
dovecot: Jul 07 14:25:31 Info: auth(default): client out: OK 1 user=xxxx@myhost.net
dovecot: Jul 07 14:25:31 Info: auth(default): ldap(xxxx@myhost.net,192.6.2.85): user search: base=ou=Users,domainName=myhost.net,o=domains,dc=myhost,dc=net scope=subtree filter=(&(mail=xxxx@myhost.net)(objectClass=mailUser)(accountStatus=active)(enabledService=mail)(enabledService=imap)) fields=storageBaseDirectory,mailMessageStore,mailQuota
dovecot: Jul 07 14:25:31 Info: auth(default): ldap(xxxx@myhost.net,192.6.2.85): Unknown user
dovecot: Jul 07 14:25:31 Error: auth(default): userdb(xxxx@myhost.net,192.6.2.85): user not found from userdb ldap
dovecot: Jul 07 14:25:31 Info: imap-login: Internal login failure (auth failed, 1 attempts): user=<xxxx@myhost.net>, method=PLAIN, rip=192.6.2.85, lip=192.6.1.203, TLS