Postfix and Linux

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Berkeley DB issues

Warning: if you can't compile Postfix because the file "db.h" isn't found, then
you MUST install the Berkeley DB development package (package name: db???-
devel-???) that comes with your Linux system. Only that package contains the
files that correspond to the Berkeley DB version that is used by the system
library routines.

DO NOT download some Berkeley DB version from the network. Every Postfix
program will dump core when it is built with a different Berkeley DB version
than the version that is used by the system library routines. See the DB_README
file for further information.

Procmail issues

On RedHat Linux 7.1 and later procmail no longer has permission to write the
mail spool directory. Workaround: chmod 1777 /var/spool/mail.

Syslogd performance

LINUX syslogd uses synchronous writes by default. Because of this, syslogd can
actually use more system resources than Postfix. To avoid such badness, disable
synchronous mail logfile writes by editing /etc/syslog.conf and by prepending a
- to the logfile name:

    /etc/syslog.conf:
        mail.*                          -/var/log/mail.log

Send a "kill -HUP" to the syslogd to make the change effective.

