mail1.sps-delivery.de has no MX records.
Question and response
Question
dig mail1.sps-delivery.de. MX
Answer
The response has no answer records.
Authority
sps-delivery.de. 300 SOA cns1.alfahosting.info. hostmaster.alfahosting.de. 2025121880 28800 7200 604800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0