dca-ans-01.inet.qwest.net has no MX records.
Question and response
Question
dig dca-ans-01.inet.qwest.net. MX
Answer
The response has no answer records.
Authority
inet.qwest.net. 300 SOA authns2.qwest.net. abuse.centurylinkservices.net. 2260219000 3600 1800 1728001 300
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0