mail.trunkoz.com has no CNAME records.
Question and response
Question
dig mail.trunkoz.com. NS
Answer
The response has no answer records.
Authority
trunkoz.com. 3595 SOA ns1.trunkoz.com. hostmaster.trunkoz.com. 2464 900 600 86400 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0