mail.walkerfire.org has no CNAME records.
Question and response
Question
dig mail.walkerfire.org. NS
Answer
The response has no answer records.
Authority
walkerfire.org. 2389 SOA ns1.way3.com. dnsadmin.way3.com. 2024121207 3600 1800 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0