--- Install ---

To install the plugin simply extract the archive to the WebApp's plugin
directory and modify the config.php file according to your needs.

Each user can enable the plugin individually via the advanced setting
'zarafa/v1/plugins/spamtrain/enable'. The default setting is determined
by the PLUGIN_SPAMTRAIN_USER_DEFAULT_ENABLE key in the config.php file.

In order to use this plugin your spam filter has to provide some kind
of command line interface to re-train it. One command to train false
negatives (spam) and one command to train false positives (ham). The
actual messages are provided via stdin to the command in RFC822-format.
See the config.php file for some common examples.
