perl.mx.develooper.com has no CNAME records.
Question and response
Question
dig perl.mx.develooper.com. NS
Answer
The response has no answer records.
Authority
develooper.com. 360 SOA ns.develooper.com. dnsoper.bitnames.com. 2026022812 600 600 4838400 360
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0