mailserver.webbytelecom.com.br has no SRV records.
Question and response
Question
dig mailserver.webbytelecom.com.br. SRV
Answer
The response has no answer records.
Authority
webbytelecom.com.br. 900 SOA dracarys.alares.network. ti\.inf.alaresinternet.com.br. 1 7200 900 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0