mailmx.ujf-grenoble.fr has no NS records.
NS records for this zone are defined at ujf-grenoble.fr.
NS records for this zone are defined at ujf-grenoble.fr.
Question and response
Question
dig mailmx.ujf-grenoble.fr. NS
Answer
The response has no answer records.
Authority
ujf-grenoble.fr. 3600 SOA eip1.u-ga.fr. dnsadmin.univ-grenoble-alpes.fr. 2018060710 3600 3600 1209600 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0