mail04.ch.umantis.com has no CNAME records.
Question and response
Question
dig mail04.ch.umantis.com. NS
Answer
The response has no answer records.
Authority
umantis.com. 3014 SOA ns1.umantis.com. hostmaster.umantis.com. 2026022501 7200 1800 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0