smpt.debitrx.com has no NS records.
NS records for this zone are defined at debitrx.com.
NS records for this zone are defined at debitrx.com.
Question and response
Question
dig smpt.debitrx.com. NS
Answer
The response has no answer records.
Authority
debitrx.com. 3600 SOA ns1.myinfra.fr. hostmaster.cegedim.com. 64645 3600 600 1209600 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0