bug.yotta.com has no MX records.
Question and response
Question
dig 9de26955a7124837965e6beadf254702.v1.radwarecloud.net. MX
Answer
The response has no answer records.
Authority
radwarecloud.net. 900 SOA ns-534.awsdns-02.net. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0