Postfix daemon processes run in the background, and log problems
and normal activity to the syslog daemon. The syslogd process sorts
events by class and severity, and appends them to logfiles. The
logging classes, levels and logfile names are usually specified in
/etc/syslog.conf. At the very least you need something like:
After changing the syslog.conf file, send a "HUP" signal to
the syslogd process.
IMPORTANT: many syslogd implementations will not create files.
You must create files before (re)starting syslogd.
IMPORTANT: on Linux you need to put a "-" character before the
pathname, e.g., -/var/log/maillog, otherwise the syslogd process
will use more system resources than Postfix.
Hopefully, the number of problems will be small, but it is a good
idea to run every night before the syslog files are rotated:
# postfix check
# egrep '(reject|warning|error|fatal|panic):' /some/log/file
The first line (postfix check) causes Postfix to report
file permission/ownership discrepancies.
The second line looks for problem reports from the mail
software, and reports how effective the relay and junk mail access
blocks are. This may produce a lot of output. You will want to
apply some postprocessing to eliminate uninteresting information.
document describes the meaning of the "warning" etc. labels in