save-mail.siidc.net has no MX records.
Question and response
Question
dig save-mail.siidc.net. MX
Answer
The response has no answer records.
Authority
siidc.net. 60 SOA ns1.siidc.net. root.ns1.siidc.net. 2010050482 10800 1800 4233600 21600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0