mx1.akamai.com has no NS records.
NS records for this zone are defined at akamai.com.
NS records for this zone are defined at akamai.com.
Question and response
Question
dig mx1.akamai.com. NS
Answer
The response has no answer records.
Authority
akamai.com. 300 SOA ns1-2.akam.net. hostmaster.akamai.com. 2026030400 7200 3600 1209600 300
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0