pdns0.den.pair.net has no MX records.
Question and response
Question
dig pdns0.den.pair.net. MX
Answer
The response has no answer records.
Authority
pair.net. 7200 SOA ns1.pair.com. root.pair.com. 2024024394 3600 300 604800 7200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0