mx02.traveltainment.de has no CNAME records.
Question and response
Question
dig mx02.traveltainment.de. NS
Answer
The response has no answer records.
Authority
traveltainment.de. 900 SOA ns01.cancom-mase.com. hostmaster.traveltainment.de. 2026021002 86400 7200 3600000 900
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0