[Exim] Failover to another LDAP server?

Hello,

in my "ldap_default_servers" option there are three or four
LDAP servers, but I have the impression that Exim doesn't remember
if a server is down (connect-timeout) and tries it for each
query again. This leads to long pauses when sending in mails, as
address verification is on and uses LDAP, too. Some clients give up and
try the secondary MX, others are rejected due to reached connection
limits (sessions are open much longer because of the timeout on the
first LDAP server). This becomes much more worse if the primary
DNS from resolv.conf is down, too...

It would be much nicer if the failover to another LDAP server were more
smoothly, similar to deferred addresses: retry in configured intervals,
automatically use secondary server until next retry time if primary
server was down.

Philip, is there any possibility to get this implemented in future
releases? :-)

Thanks,
Marc