mail-gateway.ip-projects.de has no CNAME records.
Question and response
Question
dig mail-gateway.ip-projects.de. NS
Answer
The response has no answer records.
Authority
ip-projects.de. 7670 SOA ns3.ip-projects.de. info.ip-projects.de. 2025121715 43200 7200 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0