OSEC

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Messages are not blocked when RBL has multiple DNS answers

From: JF Mezei (jfmezeivaxination.ca)
Date: Fri May 21 2010 - 04:20:09 CDT


I am new to the list.

This is on OS-X Server 10.6.3 on an Xserve with postfix 2.5.5 that came
with the system.

I have a situation where using zen.spamhaus.org , spam gets through
despite zen saying that IP is bad.

here is a sample error message:

connect from cpe-67-252-139-22.buffalo.res.rr.com [67.252.139.22]
May 19 01:09:15 velo postfix/smtpdP26473]: warning:
22.139.252.67.zen.spamhaus.org: RBL lookup error: Host or domain name
not found. Name service error for name=22.139.252.67.zen.spamhaus.org
type=A: Host not found, try again

nslookup 22.139.252.67.zen.spamhaus.org
Server: 10.0.0.20
Address: 10.0.0.20#53

Non-authoritative answer:
Name: 22.139.252.67.zen.spamhaus.org
Address: 127.0.0.10
Name: 22.139.252.67.zen.spamhaus.org
Address: 127.0.0.4

Is it possible that the postfix software barfs when the RBL lookup
returns multiple responses and lets the messsage through ?

Is there a way to fix this (other than removing zen and adding the
individual lists it contains) ?

This is a low volume server. And if I exceeded my daily quota, wouldn't
the nslookup command also fail ?