mx.ripericework.com has no NS records.
NS records for this zone are defined at ripericework.com.
NS records for this zone are defined at ripericework.com.
Question and response
Question
dig mx.ripericework.com. NS
Answer
The response has no answer records.
Authority
ripericework.com. 3600 SOA dns.ripericework.com. hostmaster.ripericework.com. 1804412891 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0