[Dovecot] sieve against ldap in Dovecot 1.2 vacation messeage

[Victor Oñate]

Hi.
I need configure "sieve" against ldap
this is my file configuration dovecot.conf

plugin {
  quota = dirsize:user
  sieve_dir = ~/sieve
}

protocol lda {
  mail_plugins = sieve
}

auth default {
  mechanisms = plain
  passdb pam {
  }
  userdb ldap {
    args = /etc/dovecot/dovecot-ldap.conf
  }
  user = nobody
}


I dont know what I have to put in dovecot-ldap.conf, ofcourse I have a
atribut in LDAP
by user with a  vacation messeage "I'm out of office, please contact Mr. Black"

this is dovecot-ldap.conf

hosts = server
auth_bind = yes

ldap_version = 3
base = dc=dominio,dc=uk
deref = never
scope = subtree


user_attrs =  
homeDirectory=home,uidNumber=uid,gidNumber=gid,mail=Maildir,mailQuotaSize=quota_rule=*:storage=%$
user_filter = (&(objectClass=posixAccount)(uid=%u))


The principal idea is keep the control the message by user with LDAP
and Dovecot(IMAP).
without touching the postfix configuration file is that possible, or
am I dreaming.

Thanks..
Victor Oñate.