perun.srv.1in1.net has no MX records.
Question and response
Question
dig perun.srv.1in1.net. MX
Answer
The response has no answer records.
Authority
1in1.net. 1800 SOA arnold.ns.cloudflare.com. dns.cloudflare.com. 2397324670 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0