cpe.sparklight.net has no MX records.
Question and response
Question
dig cpe.sparklight.net. MX
Answer
The response has no answer records.
Authority
cpe.sparklight.net. 900 SOA ns1.cableone.net. dnsadmin.cableone.net. 135 10800 3600 2592000 900
Additional
. 0 OPT ; payload 1220, xrcode 0, version 0, flags 0