mail.linux2040.webawere.nl has no CNAME records.
Question and response
Question
dig mail.linux2040.webawere.nl. NS
Answer
The response has no answer records.
Authority
linux2040.webawere.nl. 3284 SOA ns1.webawere.nl. hostmaster.linux2040.webawere.nl. 2026020700 3600 3600 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0