web.karl.systems has no MX records.
Question and response
Question
dig web.karl.systems. MX
Answer
The response has no answer records.
Authority
karl.systems. 1800 SOA ian.ns.cloudflare.com. dns.cloudflare.com. 2397141799 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0