On 2019-08-22 13:19, Gomes, Rich wrote:
I am seeing a lot of Temporary lookup failure errors in the maillog.
At first I thought it was an issue related to reverse DNS lookups as
each of the sending servers had no reverse record in DNS (this is an
internal only relay).
But when I added verbose logging, it appears to be related to LDAP
lookups.
Most commonly, I get these errors:
warning: dict_ldap_connect: Unable to bind to server ldap:….
But also receive these:
maps_find: relay_recipient_maps: u...@mydomain.com: search aborted
I can't find an exact solution for this in my searches. I realize that
a 400 level error would be re-tried but the issue is a lot of internal
apps here are not "SMTP-compliant".
Is there a timeout I can adjust or a way to cache previous searches?
The only workaround I can offer the application owners is to route
their mail to localhost and use the localhosts SmartHost setting to
route it to the preferred relay. This way localhost can handle the
retries since the application quits on anything other than a 200-level
error.
Hitting LDAP that much seems like a poor design, as it becomes expensive
(and has the other downsides you mentioned). If you must use LDAP, does
whatever you're using cache results locally so that it only hits the
network when it must (similar to what ones does with nss lookups via
nscd and friends?)
--
Coy Hile
coy.h...@coyhile.com
