web-protection.castles.pro has no MX records.
Question and response
Question
dig web-protection.castles.pro. MX
Answer
The response has no answer records.
Authority
castles.pro. 1800 SOA igor.ns.cloudflare.com. dns.cloudflare.com. 2396467955 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0