mail.m101.em.secureserver.net has no CNAME records.
Question and response
Question
dig mail.m101.em.secureserver.net. NS
Answer
The response has no answer records.
Authority
secureserver.net. 3600 SOA cns1.secureserver.net. dns.jomax.net. 2026030520 300 600 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0