ns3.twcable.com has no MX records.
Question and response
Question
dig ns3.twcable.com. MX
Answer
The response has no answer records.
Authority
twcable.com. 3600 SOA ns1.twcable.com. hostmaster.pblpdns01.twcable.com. 2026012003 14400 7200 604800 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0