outbound.geolearning.com has no MX records.
Question and response
Question
dig outbound.geolearning.com. MX
Answer
The response has no answer records.
Authority
geolearning.com. 300 SOA a1-53.akam.net. hostmaster.geolearning.com. 2022103113 3600 600 604800 300
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0