wifi.centurylink.net has no MX records.
Question and response
Question
dig wifi.centurylink.net. MX
Answer
The response has no answer records.
Authority
centurylink.net. 300 SOA authns2.qwest.net. abuse.aup.lumen.com. 2260302000 300 300 604800 300
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0