smtp.mtficore.net has no MX records.
Question and response
Question
dig smtp.mtficore.net. MX
Answer
The response has no answer records.
Authority
mtficore.net. 86400 SOA dns1.ficolo.net. hostmaster.ficolo.net. 2020051901 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0