mail2.light-speed.de has no CNAME records.
Question and response
Question
dig mail2.light-speed.de. NS
Answer
The response has no answer records.
Authority
light-speed.de. 824 SOA ns.light-speed.de. info.light-speed.de. 2025062800 21600 2700 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0