dns-nb01.aliant.net has no MX records.
Question and response
Question
dig dns-nb01.aliant.net. MX
Answer
The response has no answer records.
Authority
aliant.net. 900 SOA dns-nb00.aliant.net. hostmaster.aliant.ca. 2018041909 10800 3600 2419200 900
Additional
. 0 OPT ; payload 1220, xrcode 0, version 0, flags 0