[Exim] using director with LDAP

Hi,

i tried to configure Exim 3.35 to do a LDAP lookup to determine wich
mailboxes are local. There are several sample configs around in the web,
however, I can´t get it running.

Here is my director in exim.conf:
---------------------------------
ldapuser:
driver = smartuser
local_parts = ${lookup
ldap{ldap://xxxx.xx:389/ou=SMTP%20Service,ou=Mailaccounts,dc=brutex,dc=n
et?(mail=${local_part}@${domain})}{${local_part}}}
home_directory = ${lookup
ldap{ldap://xxxx.xx:389/ou=SMTP%20Service,ou=Mailaccounts,dc=brutex,dc=n
et?homeDirectory?(mail=${local_part}@${domain}}}{${value}}fail}
transport = my_local_delivery


Mailaccounts are stored in ou=SMTP Service, ou=Mailaccounts, dc=brutex,
dc=net and follow the CourierMailAccount Schema.

Here is a dummy entry:
----------------------
dn: cn=dummy,ou=SMTP Service,ou=Mailaccounts,dc=brutex,dc=net
gidNumber: 1000
homeDirectory: /var/mail/dummy
mail: dummy@???
uidNumber: 1000
cn: dummy
objectClass: couriermailaccount
objectClass: top


Exim logs the following:
------------------------
2004-02-01 15:09:27 1AnIHu-0000zW-00 ** dummy@???: unknown
local-part "dummy" in domain "xxxx.xx"
2004-02-01 15:09:27 1AnIHv-0000zb-00 <= <> R=1AnIHu-0000zW-00 U=mail
P=local S=2275
2004-02-01 15:09:27 1AnIHu-0000zW-00 Error message sent to xxxxxx@???
2004-02-01 15:09:27 1AnIHu-0000zW-00 Completed

I suppose the ldap search string is wrong. However, the LDAP log says,
there is something going on.
How looks a correct director directive in this case like?

Thanks
Brian Rosenberger