sms.semcabo.pt has no MX records.
Question and response
Question
dig sms.semcabo.pt. MX
Answer
The response has no answer records.
Authority
sms.semcabo.pt. 38400 SOA ns1.pt-dominios.com. geral.semcabo.pt. 1421161584 10800 3600 604800 38400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0