blastproofpoint.iu17.org has no MX records.
Question and response
Question
dig blastproofpoint.iu17.org. MX
Answer
The response has no answer records.
Authority
iu17.org. 1800 SOA coen.ns.cloudflare.com. dns.cloudflare.com. 2397190623 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0