maila01.alker.net has no CNAME records.
Question and response
Question
dig maila01.alker.net. NS
Answer
The response has no answer records.
Authority
alker.net. 1800 SOA bradley.ns.cloudflare.com. dns.cloudflare.com. 2397309111 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0