a184-51-252-6.deploy.static.akamaitechnologies.com has no MX records.
Question and response
Question
dig a184-51-252-6.deploy.static.akamaitechnologies.com. MX
Answer
The response has no answer records.
Authority
akamaitechnologies.com. 90000 SOA internal.akamaistream.net. hostmaster.akamai.com. 1559044082 90000 90000 90000 180
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0