knowl.xyz has no MX records.
Question and response
Question
dig knowl.xyz. MX
Answer
The response has no answer records.
Authority
knowl.xyz. 1800 SOA amy.ns.cloudflare.com. dns.cloudflare.com. 2396521984 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0