d01.avantel.ru has no MX records.
Question and response
Question
dig app.ia64.org. MX
Answer
The response has no answer records.
Authority
ia64.org. 1800 SOA keenan.ns.cloudflare.com. dns.cloudflare.com. 2398562589 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0