mx.tixui.com has no NS records.
NS records for this zone are defined at tixui.com.
NS records for this zone are defined at tixui.com.
Question and response
Question
dig mx.tixui.com. NS
Answer
The response has no answer records.
Authority
tixui.com. 3600 SOA ns1.cloudcity.fi. hostmaster.cloudcity.fi. 2022012401 10800 15 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0