mx.icoremail.net has no NS records.
NS records for this zone are defined at icoremail.net.
NS records for this zone are defined at icoremail.net.
Question and response
Question
dig mx.icoremail.net. NS
Answer
The response has no answer records.
Authority
icoremail.net. 180 SOA ns1.icoremail.net. postmaster.corpease.net. 2179221043 10800 3600 3888000 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0