owa.prima.com.ar has no MX records.
Question and response
Question
dig owa.prima.com.ar. MX
Answer
The response has no answer records.
Authority
prima.com.ar. 3600 SOA o200.prima.com.ar. dnsmaster.prima.com.ar. 2017011706 3600 900 3600000 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0