mail.bennettadelson.com has no CNAME records.
Question and response
Question
dig mail.bennettadelson.com. NS
Answer
The response has no answer records.
Authority
bennettadelson.com. 3205 SOA NS79.WORLDNIC.com. namehost.WORLDNIC.com. 125051310 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0