mail.flecbon.com has no CNAME records.
Question and response
Question
dig mail.flecbon.com. NS
Answer
The response has no answer records.
Authority
flecbon.com. 10800 SOA ns25.a2zcreatorz.com. ded.a2zcreatorz.com. 2026010701 3600 1800 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0