ns.secondary.net.ua has no MX records.
Question and response
Question
dig ns.secondary.net.ua. MX
Answer
The response has no answer records.
Authority
secondary.net.ua. 86400 SOA chinger.km.ua. hostmaster.secondary.net.ua. 2007102401 86400 7200 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0