pmx2.prismnet.com has no CNAME records.
Question and response
Question
dig pmx2.prismnet.com. NS
Answer
The response has no answer records.
Authority
prismnet.com. 5 SOA nsm.prismnet.com. support.prismnet.com. 2024062000 10800 3600 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0