mail.hostmar.com has no CNAME records.
Question and response
Question
dig mail.hostmar.com. NS
Answer
The response has no answer records.
Authority
hostmar.com. 10675 SOA ns1.hostmar.com. root.hostmar.com. 2025032601 28800 7200 2000000 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0