iris.mx.spoje.net has no MX records.
Question and response
Question
dig iris2.spoje.net. MX
Answer
The response has no answer records.
Authority
spoje.net. 3600 SOA ns.spoje.net. tech.spoje.net. 1771999300 3600 600 1209600 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0