mx.bsforums.com has no CNAME records.
Question and response
Question
dig mx.bsforums.com. NS
Answer
The response has no answer records.
Authority
bsforums.com. 598 SOA ns45.domaincontrol.com. dns.jomax.net. 2026021324 28800 7200 604800 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0