_spf.rexx-suite.com has no MX records.
Question and response
Question
dig _spf.rexx-suite.com. MX
Answer
The response has no answer records.
Authority
rexx-suite.com. 3600 SOA rexx-suite.com. root.rexx-suite.com. 2026021900 3600 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0