which end does the problem exist?

[/dev/rob0]

On Thu, Dec 19, 2013 at 02:48:59PM -0600,
   Lawrence K. Chen, P.Eng. wrote:
> Got reports that users are unable to send mail to usda.gov
> sites using our campus SMTP server (where we have usda.gov
> sites on campus.)
> 
> The users have said they were able to send using other servers
> like Google and Microsoft.
> 
> When I look at my system, its unable to resolve the domain name.

Dec 19 14:51:43 chestnut named[11604]: validating @0x7f17880be380: 
usda.gov DNSKEY: no valid signature found (DS)

DNSSEC failure on their end.
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