Something wrong with the mail services

SYSTEM INFORMATION
OS type and version centos 7
Webmin version 2.0
Virtualmin version 7.3
Related packages SUGGESTED

something is really wrong with the mail services postfix and dovecot was working fine before the last update now postfix gives always timeout and dovecot receive nothing what is really wrong can somebody help not only the logs to look but if i look the logs where they are and what should i look now nothing regarding the mail is working.

Duplicate of Thunderbird unable to connect to SMTP server