ns1.pulnet.ru has no MX records.
Question and response
Question
dig ns1.pulnet.ru. MX
Answer
The response has no answer records.
Authority
pulnet.ru. 3600 SOA ns1.pulnet.ru. root.pulnet.ru. 2026011601 3600 900 3600000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0