relay2.agava.com has no MX records.
Question and response
Question
dig relay2.agava.com. MX
Answer
The response has no answer records.
Authority
agava.com. 10800 SOA ns1.agava.net.ru. hostmaster.ns1.agava.net.ru. 1755902462 14400 3600 604800 10800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0