_spf.transip.email has no MX records.
Question and response
Question
dig _spf.transip.email. MX
Answer
The response has no answer records.
Authority
transip.email. 3600 SOA ns0.transip.net. hostmaster.transip.nl. 2026021900 14400 1800 2419200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0