relay13.mta.mpssec.net has no CNAME records.
Question and response
Question
dig relay13.mta.mpssec.net. NS
Answer
The response has no answer records.
Authority
mpssec.net. 3600 SOA ns11.mpssec.net. hostmaster.anubisnetworks.com. 2025111042 7200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0