mx02.netcarrier.net has no CNAME records.
Question and response
Question
dig mx02.netcarrier.net. NS
Answer
The response has no answer records.
Authority
netcarrier.net. 10800 SOA ns1.netcarrier.net. postmaster.netcom.netcarrier.com. 2026010601 500 300 3600000 10800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0