[Exim] "smtp auth login" and ldap

Hi,

i've a little question :)

how to confituge "smtp auth login" to search the passwords on a ldap server?
i try the follow configuration, but outlook don't find the password:

ldap_smtp_auth_login:
driver = plaintext
public_name = LOGIN
server_prompts = "Username:: : Password::"
server_condition = "ldap://127.0.0.1:389/c=DE?uname?sub?(password=*: ${local_part}:*)"
server_set_id = $1

the ldappath is the same as to search the aliases. the searching for aliases
does works, but the password (as plaintext in the ldapserver) will don't works.
have you any idea why?

thx
Tobias