dns02.net4all-dns.com has no MX records.
Question and response
Question
dig dns02.net4all-dns.com. MX
Answer
The response has no answer records.
Authority
net4all-dns.com. 300 SOA dns01.net4all-dns.com.net4all-dns.com. hostmaster.net4all-dns.com. 2022053006 10800 3600 2592000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0