[exim] problem with "\n" in a transport text

Hello.

In a vacation transport, i use the directive above:

uservacation_transport:
    driver                      = autoreply
    subject                     = "Re: $h_subject"
    text                        = "${lookup ldap \
         {LDAP_SERVER/LDAP_VACATION_MSG_QUERY}}\n\
                Ce message vous est envoye par un robot.\n\
                Il ne vous sera adresse qu'une fois."
    log    = /var/spool/exim4/vacation/${local_part}@${domain}-log
    once  = /var/spool/exim4/vacation/${local_part}@${domain}-once
    once_file_size              = 2K
    #once_repeat                = 7d
    to                          = ${sender_address}
    from                        = ${local_part}@${domain}
    user                        = Debian-exim

My problem is that the use of the line return (\n) don't run correctly....
How is it possible in my config to di the "\n" active in the return mail?

Thank's for your help.

- -
E.Bullier