googlestring.bluecoatcloud.com has no MX records.
Question and response
Question
dig googlestring.bluecoatcloud.com. MX
Answer
The response has no answer records.
Authority
bluecoatcloud.com. 120 SOA ns1-253.akam.net. hostmaster.akamai.com. 1553197571 43200 7200 604800 120
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0