SERVFAIL for a few recurring domains

Fri Dec 7 16:22:30 UTC 2001

We continue to get a SERVFAIL for a few recurring domains when trying to
send them email. But this is an intermittent problem. 
The domains are:

Samsung.co.kr
mic.com.tw 
hpcoho.com
Digitalcommerce.com
infomail.co.kr
rocketchips.com
accusort.com
amkor.com
goscs.com
samsung.com
zaiqtech.com
afere.com

If I let the messages sit in the queue, sometime they will eventually get
sent.

We are running BIND 8.2.4, on Solaris

We have verified that sendmail is not configured to not require the AA flag
be set.

We have disabled negative cache right now for testing and troubleshooting,
by setting negative cache to 0.

If I dig for the domain A or MX records I get a servfail, if I did for NS
records I get them. If I set my server to the ones listed for the NS records
I find the A and MX records. But switching back to our name server and then
looking up the MX will fail again with a servfail messages.

I have since setup some test "forward zones" in our named.conf  for the
domains that keep recurring. Since doing so those domains not longer seem to
represent a problem.

Why am I able to forward all request for a specific domain to there name
servers and everything works fine. But if I remove the forward zone from the
named.conf file, our name server start having problems finding the MX
records? I have verified that the root servers in our db.cache file are
current.

This problem has been puzzling me for quite a while, and any help would be
great appreciated.

-Bob