ns.o04.xemis.net has no MX records.
Question and response
Question
dig ns.o04.xemis.net. MX
Answer
The response has no answer records.
Authority
o04.xemis.net. 38400 SOA ns.o04.xemis.net. postmaster.o04.xemis.net. 2025021102 10800 3600 1209600 38400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0