[ale] mail troubles today

[Jeff Dilcher]

Hello all.

I have a linux box in the net' which has 
qmail running, and is called cueva.penguinpowered.com.

It should be receiving mail (it has in the past) via
Qmail which I installed.

Today I couldn't send mail to the box from other 
sites.  Here is the bounced mail message:

jdilcher at cueva.penguinpowered.com... Deferred: Name server:
cueva.penguinpowered.com.: host name lookup failure
Warning: message still undelivered after 4 hours
Will keep trying until message is 1 week old

Seems like the sender's box can't lookup the hostname,
but if I run nslookup, I see the proper TCP address
gets displayed.

Anyone know what could be happening?  This is happening
from more than one sender site, so I think the problem
must be with my dns somehow, or my box.

Thanks!