mx.vivvaa.com has no NS records.
NS records for this zone are defined at vivvaa.com.
NS records for this zone are defined at vivvaa.com.
Question and response
Question
dig mx.vivvaa.com. NS
Answer
The response has no answer records.
Authority
vivvaa.com. 3600 SOA dns.vivvaa.com. hostmaster.vivvaa.com. 1888802325 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0