mx1-eu.vivawebhost.com has no CNAME records.
Question and response
Question
dig mx1-eu.vivawebhost.com. NS
Answer
The response has no answer records.
Authority
vivawebhost.com. 3937 SOA ns1.vivawebhost.com. root.vivawebhost.com. 2026021700 1800 7200 2419200 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0