mail.zummer.su has no NS records.
NS records for this zone are defined at zummer.su.
NS records for this zone are defined at zummer.su.
Question and response
Question
dig mail.zummer.su. NS
Answer
The response has no answer records.
Authority
zummer.su. 3600 SOA ns1.svols.com. admin.svols.com. 2025121700 3600 900 3600000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0