postfix_memcached is a patch to Postfix (2.1 and
2.2) to allow it to use memcache as a map source.
The memcache map type can be used to reduce the
load on another map type, e.g. pgsql. By placing
the memcache map before the pgsql map, a key not
found in the memcache will fall through to the
database. You'll need to figure out a way to
reverse populate the cache from the database
yourself. This map type can be seen as an
alternative to the proxymap(8) service.
