PPoossttffiixx aanndd LLiinnuuxx

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BBeerrkkeelleeyy DDBB iissssuueess

Warning: if you can't compile Postfix because the file "db.h" isn't found, then
you MUST install the Berkeley DB development package (name: db???-devel-???)
that matches your system library. You can find out what is installed with the
rpm command. For example:

    $ rrppmm --qqff //uussrr//lliibb//lliibbddbb..ssoo
    db4-4.3.29-2

This means that you need to install db4-devel-4.3.29-2 (on some systems,
specify /lib/libdb.so in the rpm query).

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.

PPrrooccmmaaiill iissssuueess

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

SSyyssllooggdd ppeerrffoorrmmaannccee

LINUX ssyyssllooggdd uses synchronous writes by default. Because of this, ssyyssllooggdd 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 "kkiillll --HHUUPP" to the ssyyssllooggdd to make the change effective.