_spf.drei.host has no MX records.
Question and response
Question
dig _spf.drei.host. MX
Answer
The response has no answer records.
Authority
drei.host. 3600 SOA adns1.drei.com. at\.dns.drei.com. 2026011601 14400 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0