Checking Logs The file /etc/syslog.conf contains a line that is used to copy all mail by syslogd (CentOS). Note that Suse uses syslog-ng and so that config file is found at /etc/syslog-ng/syslog-ng.conf (see below). Here is that line(CentOS): # Log all the mail messages in one place. mail.* -/var/log/maillog So the location of the maillog is listed and you can use this command to locate the most notable issues with Postfix. # ...