correo.optical.com.pe has no CNAME records.
Question and response
Question
dig correo.optical.com.pe. NS
Answer
The response has no answer records.
Authority
optical.com.pe. 3600 SOA ns1.opticalip.com.pe. hostmaster.opticalip.com.pe. 2025052300 3600 1800 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0