ns4.iphh.net has no MX records.
Question and response
Question
dig ns4.iphh.net. MX
Answer
The response has no answer records.
Authority
iphh.net. 7200 SOA ns1.iphh.de. hostmaster.iphh.net. 2026021603 43200 7200 2419200 7200
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0