OpenSMTPD extras - backends for OpenSMTPD tables, schedulers, queues
and filters

Allows using different backends for OpenSMTPD tables, schedulers, queues
and filters, including SQLite, MySQL, PostgreSQL, LDAP...

Each backend can be activated or deactivated by setting the relevant env
var to yes or no. By default, Password, MySQL and SQLite table backends
are built, since they are pretty straightforward to use, and everything
is available on a stock Slackware installation.

* Tables:
TLDAP=no
TMYSQL=yes
TPOSTGRES=no   # requires potgresql
TREDIS=no      # requires hiredis and redis
TSOCKETMAP=no
TPASSWORD=yes
TPYTHON=no
TSQLITE=yes
TSTUB=no
* Queues:
QNULL=no
QPYTHON=no
QRAM=no
QSTUB=no
* Schedulers:
SRAM=no
SSTUB=no
SPYTHON=no
* Filters:
FMONKEY=no
FSTUB=no
FTRACE=no
FVOID=no
* Other:
STATS=no   # enable tool stats
