mx2.ip.tiscali.net has no CNAME records.
Question and response
Question
dig mx2.ip.tiscali.net. NS
Answer
The response has no answer records.
Authority
ip.tiscali.net. 300 SOA pns.tinet.net. netguard.tinet.net. 2026022400 86400 7200 3600000 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0