mail.letter.is has no NS records.
NS records for this zone are defined at letter.is.
NS records for this zone are defined at letter.is.
Question and response
Question
dig mail.letter.is. NS
Answer
The response has no answer records.
Authority
letter.is. 3600 SOA dns1.technofaq.org. hostmaster.letter.is. 2026031002 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0