hlrn.qwest.net has no MX records.
Question and response
Question
dig hlrn.qwest.net. MX
Answer
The response has no answer records.
Authority
hlrn.qwest.net. 86400 SOA authns1.qwest.net. dns-admin.qwestip.net. 2250505001 10800 3600 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0