_spf_mtab.drei.at has no MX records.
Question and response
Question
dig _spf_mtab.drei.at. MX
Answer
The response has no answer records.
Authority
drei.at. 30 SOA adns3.drei.com. dns.drei.com. 2026021910 10800 3600 2419200 30
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0