• The common whitelist of email addresses contains the addresses from the whitelists of connected plug-ins. The plug-in adds to common whitelist the senders from messages marked as non-spam in email client and the addresses added to whitelist manually. The senders from messages marked as spam and added to blacklist manually are deleted from common whitelist automatically.
  
• The common database of messages contains the descriptors of messages marked as spam or non-spam. The descriptors contain the information necessary for training the plug-ins connected to SniperSync server.

Two-way synchronization is organized using a SniperSync server, which can be installed on one of the computers in local network. The server address and port must be entered in Synchronization settings, on Options tab of plug-in configuration window. The default server port is 17080. If the server is installed locally, enter 127.0.0.1 as host name.

The synchronization can run in background. The plug-in will connect to SniperSync automatically, using the specified interval. Also it is possible to execute the synchronization manually, using the corresponding button. By default the plug-in downloads the updates incrementally, i.e. it downloads only changes since the last synchronization. Answering No in a message box displayed before starting the manual synchronization will make the plug-in to download all updates.

The common whitelist items are stored locally for better performance. It is possible to clear this local cache and download a copy of the whitelist from server.

The message descriptors from common database are applied to the trainable classifier. But the plug-in makes its best to keep the classification results the same for the messages marked as spam or ham by yourself. I.e. the manual training has a higher priority. So you can always train the plug-in to make it classify the messages as you want, even when it uses SniperSync server.