_spf6.maas360.com has no MX records.
Question and response
Question
dig _spf6.maas360.com. MX
Answer
The response has no answer records.
Authority
maas360.com. 3600 SOA a1-64.akam.net. networkadmin.wwpdl.vnet.ibm.com. 2021072088 10800 3600 1209600 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0