_dmarc.bancotui.com has no CNAME records.
Question and response
Question
dig _dmarc.bancotui.com. NS
Answer
The response has no answer records.
Authority
bancotui.com. 3437 SOA dns1.cloud.claro.com.do. bancotui.claro.net.do. 3110620 14400 7200 2419200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0