mails.liveperson.net has no NS records.
NS records for this zone are defined at liveperson.net.
NS records for this zone are defined at liveperson.net.
Question and response
Question
dig mails.liveperson.net. NS
Answer
The response has no answer records.
Authority
liveperson.net. 7200 SOA a1-175.akam.net. hostmaster.asia1.akam.net. 4138621333 14400 7200 1209600 7200
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0