smtp3.i4ip.net has no CNAME records.
Question and response
Question
dig smtp3.i4ip.net. NS
Answer
The response has no answer records.
Authority
i4ip.net. 3600 SOA ns1.h4hosting.eu. hostmaster.h4hosting.eu. 2026021604 3600 3600 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0