srs01-b.satorimail.net has no MX records.
Question and response
Question
dig srs01-b.satorimail.net. MX
Answer
The response has no answer records.
Authority
satorimail.net. 900 SOA ns-1056.awsdns-04.org. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0