smp01.mailmerc.com has no CNAME records.
Question and response
Question
dig smp01.mailmerc.com. NS
Answer
The response has no answer records.
Authority
mailmerc.com. 300 SOA ns1.protected.ca. hostmaster.protected.ca. 2024081540 3600 900 1209600 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0