inprofu.edu.do.spf.auto.dnssmarthost.net has no MX records.
Question and response
Question
dig _4a8d0e84e46b24b9be9f885821e5d800.spf.dnssmarthost.net. MX
Answer
The response has no answer records.
Authority
spf.dnssmarthost.net. 86400 SOA ns1.spf.dnssmarthost.net. admins.siteground.com. 9097826 86400 7200 3600000 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0