mx1.imcsas.com.co has no NS records.
NS records for this zone are defined at imcsas.com.co.
NS records for this zone are defined at imcsas.com.co.
Question and response
Question
dig mx1.imcsas.com.co. NS
Answer
The response has no answer records.
Authority
imcsas.com.co. 86400 SOA ns1.colombiahosting.com. sysadmin.colombiahosting.com.co. 2026011100 3600 1800 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0