sender049.builderallmail.com has no MX records.
Question and response
Question
dig sender049.builderallmail.com. MX
Answer
The response has no answer records.
Authority
builderallmail.com. 600 SOA ns65.domaincontrol.com. dns.jomax.net. 2023091900 28800 7200 604800 600
Additional
. 0 OPT ; payload 1280, xrcode 0, version 0, flags 0