mail6.springleaf.com has no NS records.
NS records for this zone are defined at springleaf.com.
NS records for this zone are defined at springleaf.com.
Question and response
Question
dig mail6.springleaf.com. NS
Answer
The response has no answer records.
Authority
springleaf.com. 86400 SOA ns1.markmonitor.com. hostmaster.markmonitor.com. 2025081501 86400 3600 2592000 172800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0