cloud.microsoft has no MX records.
Question and response
Question
dig cloud.microsoft. MX
Answer
The response has no answer records.
Authority
cloud.microsoft. 60 SOA ns1-33.azure-dns.com. azuredns-hostmaster.microsoft.com. 1 3600 120 2419200 60
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0