On 9/10/2019 1:44 PM, J Doe wrote:
Hello,I have a question regarding DNSBL usage with the main.cf smtpd_client_restrictions parameter. I have a server configured to check SpamHaus: main.cf . . . smtpd_client_restrictions = reject_rbl_client zen.spamhaus.org=127.0.0.[2..11], . . . This has been working very well, although I noticed the following error in my syslog: Sep 7 16:13:08 server postfix/smtpd[28363]: warning: 188.50.102.94.zen.spamhaus.org: RBL lookup error: Host or domain name not found. Name service error for name=188.50.102.94.zen.spamhaus.org type=A: Host not found, try again I am wondering - in normal checks against SpamHaus, if a host is not listed and the result is NXDOMAIN, I am assuming that Postfix interprets that the host is “ok” and does not log any information. In this case, though, it has logged the information and I am wondering if this is because Postfix was unable to contact SpamHaus at all, not just regarding the record: 188.50.102.94.zen.spamhaus.org ? Thanks, - J
Lookup error: means something didn't work; your DNS told postfix it couldn't find spamhaus at all, but it was a temporary error so try again. Postfix will ignore the result.
If you get this rarely, it's nothing to worry about. If it happens often, there may be a problem with your DNS server or network connection.
-- Noel Jones
