mx2.online.pt has no NS records.
NS records for this zone are defined at online.pt.
NS records for this zone are defined at online.pt.
Question and response
Question
dig mx2.online.pt. NS
Answer
The response has no answer records.
Authority
online.pt. 86400 SOA trinity.tuxdns.com. cpanel.online.pt. 2026030524 3600 1800 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0