ok.shawcable.net has no MX records.
Question and response
Question
dig ok.shawcable.net. MX
Answer
The response has no answer records.
Authority
ok.shawcable.net. 600 SOA ns1.ht.ok.shawcable.net. dnsadmin.shaw.ca. 2150506590 10800 3600 604800 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0