The plug-in starts filtering spam immediately after the installation. It classifies the incoming messages and moves recognized spam to appropriate folders. The messages with high spam ratio are moved to folder "Junk E-mail" and the messages with average spam ratio are moved to "Unsure E-mail". Use the following options on General page for customizing this behavior:

• Move a message to the Junk folder if the score is greater than
  Defines the minimum number of points needed to automatically move a message to the Junk folder. The higher value you set, the higher probability of false negatives you get (when spam is misclassified as normal message). On the other hand, the probability of false positives becomes lower in that case (when normal messages are misclassified as spam). The default value is 80 and it is good enough in most cases. If you set it to 85-95, you will probably get more misclassified spam in your mailbox, but the probability of false positives will be lower.
• Folder for Junk messages
  You can select a folder for moving there Junk messages.
• Mark stored mail as read.
  This is self-explainatory option and it is convenient to have it enabled.
• Move messages marked as junk to the Junk folder.
  If this option is enabled, messages will be moved to the Junk folder automatically when you mark them as spam.
• Move a message to the Unsure folder if the score is greater than
  Defines the minimum number of points needed to automatically move a message to the Unsure folder. The messages with a spam ratio lower than for Junk, but higher than this minimum, will be recognized as Unsure.
• Folder for Unsure messages
  You can select a folder for moving there Unsure messages.
  
  
• Do not filter these folders
  You can disable filtering for some folders. Note, that this parameter affects only POP3 accounts. The IMAP accounts have their own settings.

If you have some normal and spam messages in your email client, it makes sense to train the plug-in using them. To train the plug-in you can use the toolbar buttons "Mark as Junk" and "Mark as Good". Select one or more messages of either class and press one of the buttons. For convenience you can specify shortcuts for these actions.

The whitelist is filled automatically when you are training the filter using non-spam messages. The more non-spam messages you mark, the more contacts will be listed. Messages from friendly addresses are not filtered and it is the best protection against being misclassified by other methods. The classifier needs messages of both classes. So feed it also with your junk messages if you have any.

Tune up the DNSBL, URIBL and Black words mechanisms in order to filter messages by their headers. To allow the plug-in to delete spam by message headers on the server and enable filtering IMAP accounts, fill up the list of accounts on the Accounts tab. By default the plug-in does this automatically for the connections with standard POP3 and IMAP ports. If your server uses non-standard ports, it is possible to add the accounts manually and specify the required ports in account properties.

You can continue using the email client as usual. It is necessary to review the Filtering Log and search for misclassified messages. It is especially important in the beginning when the plug-in is not trained enough to avoid false positives. The probability of such mistakes will get lower fast if you train the plug-in.