pgg2b2.bf01.hubspotstarter.net has no MX records.
Question and response
Question
dig pgg2b2.bf01.hubspotstarter.net. MX
Answer
The response has no answer records.
Authority
hubspotstarter.net. 1800 SOA jerry.ns.cloudflare.com. dns.cloudflare.com. 2398134633 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0