mail.apple.com.mx has no NS records.
NS records for this zone are defined at apple.com.mx.
NS records for this zone are defined at apple.com.mx.
Question and response
Question
dig mail.apple.com.mx. NS
Answer
The response has no answer records.
Authority
apple.com.mx. 300 SOA ns-ext-prod.jackfruit.apple.com. dnscontact.apple.com. 2025051400 14400 5400 3628800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0