mx2.prewise.com has no CNAME records.
Question and response
Question
dig mx2.prewise.com. NS
Answer
The response has no answer records.
Authority
prewise.com. 3443 SOA ns1.prewise.com. hostmaster.prewise.com. 2025022701 1200 600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0