ns.planeetta.org has no MX records.
Question and response
Question
dig ns.planeetta.org. MX
Answer
The response has no answer records.
Authority
planeetta.org. 1800 SOA matt.ns.cloudflare.com. dns.cloudflare.com. 2394990933 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0