ca.216.202.167.132.gtecablemodem.com has no MX records.
Question and response
Question
dig ca.216.202.167.132.gtecablemodem.com. MX
Answer
The response has no answer records.
Authority
gtecablemodem.com. 86400 SOA dnsauth1.sys.gtei.net. dns.level3.net. 2008061076 3600 900 864000 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0