[exim] LDAP queries against AD, and LDAP error 8: Strong(er…

I'm trying to do some queries from exim (4.84.2-2+deb8u3) to an AD LDAP
server (Samba4.2, but i think make little difference).

Following:
    https://github.com/Exim/exim/wiki/MsExchangeAddressVerification

i've correctly make a test query, but i was forced to disable ''stronger
auth'', eg put in smb.conf:

    ldap server require strong auth = no

even the value:

    ldap server require strong auth = allow_sasl_over_tls

does not work.

(as stated smb.conf manpage: «A value of allow_sasl_over_tls allows simple
and sasl binds (without sign or seal) over TLS encrypted connections.
Unencrypted connections only allow sasl binds with sign or seal.»)


I've tried to explicitly use ldaps:///, but bind failed.


I'm doing something wrong or really it is needed to disable stronger auth?
When connecting exim write:

    LDAP_OPT_X_TLS_TRY set due to ldap:// URI

so seems that at least try to connect with tls...


Thanks.

-- 
  Non mi interessa sentirmi intelligente guardando in tv dei cretini,
  preferirei sentirmi un cretino di fronte a persone eccellenti.
                        (Franco Battiato)