edgmailer51.broadridge.com has no CNAME records.
Question and response
Question
dig edgmailer51.broadridge.com. NS
Answer
The response has no answer records.
Authority
broadridge.com. 3600 SOA edns1.ultradns.com. enterprisedns.broadridge.com. 2026011157 600 3600 691200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0