Errors.current: Tousends of "..Received an invalid DNS.

Question

In our file "errors.current", we have many tousends of such entries:
Fri Feb 1 13:24:49 2008 Warning: Received an invalid DNS Response: rcode=ServFail data="'\\x8e\\x85\\x81\\x82\\x00\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x0edrillerssupply\\x03com\\x00\\x00\\x0f\\x00\\x01'" to IP 10.168.3.24 looking up drillerssupply.com
What's about the above IP 10.168.3.24?
(Is this IP sending or receving a mail? Whats the meaning of this IP?)
Nearly all entries occures in combination with only 3 IPs. None of this IP is a mailserver or ironport.
What exactly can I do to minimize or prevent such entries?

Answer 1

This indicates that DNS server 10.168.3.24 returned a 'servfail' when it attempted to lookup domain 'drillerssupply.com' in DNS. SERVFAIL means that the domain does exist and the root name servers have information on this domain, but that the authoritative name servers are not answering queries for this domain.
I got a 'servfail' response when i attempted to lookup this domain from my workstation.
bash-3.00# dig MX drillerssupply.com
; <<>> DiG 9.2.4 <>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 7332
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;drillerssupply.com. IN MX
;; Query time: 178 msec
;; SERVER: 172.17.128.3#53(172.17.128.3)
;; WHEN: Mon Feb 4 16:52:10 2008
;; MSG SIZE rcvd: 36
Seeing lots of these messages in the logs indicates that there are lots of emails going to sites that have garbaged DNS replies. It would also mean that the local DNS server is flaky. Based upon this particular example, i would lean on the former.