mailer0.gate85.rs.smtp.com has no NS records.
NS records for this zone are defined at rs.smtp.com.
NS records for this zone are defined at rs.smtp.com.
Question and response
Question
dig mailer0.gate85.rs.smtp.com. NS
Answer
The response has no answer records.
Authority
rs.smtp.com. 900 SOA ns-574.awsdns-07.net. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0