Transient parse error - self-resolved after nslookup?

[Carl Houseman]

Had a message in the queue since April 10, every time it tried to deliver, it logged:

Apr 15 13:31:59 hpr sendmail[27430]: QAA27597: to=RECIPIENT@DOMAIN.COM, delay=4+20:35:18, mailer=relay, relay=vega.ourdomain.com, stat=Transient parse error -- message queued for future delivery

All other mail was working fine. I read some other threads suggesting DNS issues, so I did some checking with nslookup on the host. Everything looked fine. The only weird thing was, if I checked for mx records with the domain name as DOMAIN.COM (all uppercase), the MX servers were listed in lowercase, and if I checked for domain.com (all lowercase), the MX servers were given in uppercase.

Soon after doing those nslookups, the message was delivered.

What happened here? Do I need a patch?

HP-UX 11.11 if it matters. TIA.

[Carl Houseman]

Some further info... it seems only the first nslookup that succeeded returned the MX servers in uppercase, and it looked like this:

# nslookup -type=MX hobbittravel.com
Using /etc/hosts on: hpr
looking up FILES
Trying DNS
Non-authoritative answer:
domain.com preference = 10, mail exchanger = SMTP1.HOST1.DOMAIN.com
domain.com preference = 20, mail exchanger = SMTP1.HOST2.DOMAIN.com

Thereafter subsequent nslookups with domain in uppercase have returned:

# nslookup -type=MX DOMAIN.COM
Using /etc/hosts on: hpr
looking up FILES
Trying DNS
Non-authoritative answer:
DOMAIN.COM preference = 10, mail exchanger = smtp1.host1.domain.COM
DOMAIN.COM preference = 20, mail exchanger = smtp1.host2.domain.COM

Authoritative answers can be found from:
smtp1.host1.domain.COM internet address = x.x.x.x
smtp1.host2.domain.COM internet address = 204.11.209.99

If I nslookup domain.com (all lowercase) the MX hosts are returned as smtp1.host1.domain.com instead of smtp1.host1.domain.COM