mail01.psni.com has no MX records.
Question and response
Question
dig mail01.psni.com. MX
Answer
The response has no answer records.
Authority
psni.com. 86400 SOA ns-1.nuoz.net. postmaster.nwnexus.com. 2024052900 7200 3600 864000 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0