mx.cnetworks.lv has no CNAME records.
Question and response
Question
dig mx.cnetworks.lv. NS
Answer
The response has no answer records.
Authority
cnetworks.lv. 73 SOA bind.cnetworks.lv. admin.cnetworks.lv. 131 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0