sms.tigo.com.bo has no CNAME records.
Question and response
Question
dig sms.tigo.com.bo. NS
Answer
The response has no answer records.
Authority
tigo.com.bo. 889 SOA dns1.wimaxtigo.bo. please_set_email.absolutely.nowhere.tigo.com.bo. 2025120809 10800 10800 2419200 900
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0