smtp7.agroweb.nl has no CNAME records.
Question and response
Question
dig smtp7.agroweb.nl. NS
Answer
The response has no answer records.
Authority
agroweb.nl. 3329 SOA ns1.agroweb.nl. postmaster.agroweb.nl. 2025060200 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0