mail1.mazdadsg.com has no CNAME records.
Question and response
Question
dig mail1.mazdadsg.com. NS
Answer
The response has no answer records.
Authority
mazdadsg.com. 2517 SOA fh-dns1.minacs.com. hostmaster.minacs.com. 134 900 600 86400 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0