ns1.dattobackup.com has no MX records.
Question and response
Question
dig ns1.dattobackup.com. MX
Answer
The response has no answer records.
Authority
dattobackup.com. 3500 SOA ns1.dattobackup.com. dns.dattobackup.com. 2019119003 28800 7200 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0