I can't view any detailed log for Postfix under Centos

Solution 1:

is your syslogd setup to log stuff to maillog? like following:

[alexus@wcmisdlin02 ~]$ grep ^mail /etc/rsyslog.conf 
mail.*                                                  -/var/log/maillog
[alexus@wcmisdlin02 ~]$ 

also make sure it's running

[alexus@wcmisdlin02 ~]$ sudo service rsyslog status
rsyslogd (pid  1356) is running...
[alexus@wcmisdlin02 ~]$ 

Solution 2:

I had the same log problem on CentOS-7 with postfix but also with any logger command like: 'logger System testing my log'

Checking deeper, I found out that Rsyslogd was not listening anymore on /dev/log socket !!!! This can be checked with 'lsof /dev/log'

I fixed the problem, by forcing /dev/log in /etc/rsyslogd.conf.
-- after $ModLoad imuxsock -- add this next line input(type="imuxsock" HostName="localhost" Socket="/dev/log")

This will force usage of /dev/log, which after my last update was no more the default. This is probably a bug. I have the problem with rsyslog-7.4.7-7.el7_0.x86_64 or