mgw.suantispam.com has no CNAME records.
Question and response
Question
dig mgw.suantispam.com. NS
Answer
The response has no answer records.
Authority
suantispam.com. 3600 SOA ns1.interplanet.com.mx. hostmaster\@interplanet.com.mx. 2022025934 7200 3600 604800 43200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0