45-236-13-23.sdgtelecom.com.br has no MX records.
Question and response
Question
dig 45-236-13-23.sdgtelecom.com.br. MX
Answer
The response has no answer records.
Authority
sdgtelecom.com.br. 3600 SOA ns.sdgtelecom.com.br. root\@ns.sdgtelecom.com.br. 2025101101 3600 900 3600000 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0