mail.ddays2.sci.uz has no CNAME records.
Question and response
Question
dig mail.ddays2.sci.uz. NS
Answer
The response has no answer records.
Authority
ddays2.sci.uz. 1765 SOA hosting.scinet.uz. davronaka.yahoo.com. 1770677039 10800 3600 604800 10800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0