mailbox.cloudmail.ondemand.com has no MX records.
Question and response
Question
dig mailbox.cloudmail.ondemand.com. MX
Answer
The response has no answer records.
Authority
cloudmail.ondemand.com. 7200 SOA ns1.sap.net. dns.sap-ag.de. 2019030348 3524 600 3600000 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0