689541752.box.freepro.com has no MX records.
Question and response
Question
dig 689541752.box.freepro.com. MX
Answer
The response has no answer records.
Authority
box.freepro.com. 3600 SOA ns1.freepro.com. dnsadmin.freepro.com. 30781 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0