mail-central1.forefieldkt.com has no CNAME records.
Question and response
Question
dig mail-central1.forefieldkt.com. NS
Answer
The response has no answer records.
Authority
forefieldkt.com. 1270 SOA edns1.ultradns.com. enterprisedns.broadridge.com. 2019092234 86400 86400 86400 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0