pop.termil.com.br has no NS records.
NS records for this zone are defined at termil.com.br.
NS records for this zone are defined at termil.com.br.
Question and response
Question
dig pop.emaipop.lexchangeonline.com. NS
Answer
The response has no answer records.
Authority
lexchangeonline.com. 3601 SOA dns1.registrar-servers.com. hostmaster.registrar-servers.com. 1771668992 43200 3600 604800 3601
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0