hosting.smartspb.net has no MX records.
Question and response
Question
dig hosting.smartspb.net. MX
Answer
The response has no answer records.
Authority
hosting.smartspb.net. 600 NS plesk.smartspb.net.
Additional
plesk.smartspb.net. 600 A 217.119.16.109
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0