grievous.cf.fastservers.net has no MX records.
Question and response
Question
dig grievous.cf.fastservers.net. MX
Answer
The response has no answer records.
Authority
fastservers.net. 14400 SOA ns1.datapipe.net. admin.fastservers.net. 2020040710 10800 3600 604800 14400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0