_mx.prq.se has no CNAME records.
Question and response
Question
dig _mx.prq.se. NS
Answer
The response has no answer records.
Authority
prq.se. 284 SOA ns1.dnsserv.se. registry.dnsserv.se. 2025021824 10800 3600 1814400 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0