mx3.prewise.com has no CNAME records.
Question and response
Question
dig mx3.prewise.com. NS
Answer
The response has no answer records.
Authority
prewise.com. 3599 SOA ns1.prewise.com. hostmaster.prewise.com. 2025022701 1200 600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0