ns4.dnssunucu.com has no MX records.
Question and response
Question
dig ns4.dnssunucu.com. MX
Answer
The response has no answer records.
Authority
dnssunucu.com. 3600 SOA ns1.dnssunucu.com. hostmaster.pusula.net.tr. 2023121801 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0