mail.garnethill.com has no CNAME records.
Question and response
Question
dig mail.garnethill.com. NS
Answer
The response has no answer records.
Authority
garnethill.com. 42 SOA ns3.qvc.com. hostmaster.garnethill.com. 2025071620 10800 3600 2419200 60
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0