mail.ipxgate.com has no CNAME records.
Question and response
Question
dig mail.ipxgate.com. NS
Answer
The response has no answer records.
Authority
ipxgate.com. 8033 SOA ns01.ipxgate.com. ikonomidis.gmail.com. 1305185602 10800 3600 1209600 38400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0