ns1.centurytel.NET has no MX records.
Question and response
Question
dig ns1.centurytel.NET. MX
Answer
The response has no answer records.
Authority
centurytel.net. 300 SOA authns1.qwest.net. abuse.centurylinkservices.net. 2251009000 300 300 604800 300
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0