mx.alog.com.br has no CNAME records.
Question and response
Question
dig mx.alog.com.br. NS
Answer
The response has no answer records.
Authority
alog.com.br. 3515 SOA dns1.p07.nsone.net. hostmaster.nsone.net. 1649794102 1200 600 43200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0