mail.dc.volia.com has no NS records.
NS records for this zone are defined at dc.volia.com.
NS records for this zone are defined at dc.volia.com.
Question and response
Question
dig mail.dc.volia.com. NS
Answer
The response has no answer records.
Authority
dc.volia.com. 3600 SOA ns0.dc.volia.com. hostmaster.dc.volia.com. 2025052900 14400 3600 604800 3600
Additional
The response has no additional records.