VPOP3 supports plugins which can process messages at various stages. To access the plugin configuration, go to Utilities -> VPOP3 Plugins.
The plugin list shows the various plugins you have installed. Plugins can support up to 4 types of operation. Download Rules, SMTP Rules, Message Processing, or Password Checking.
The Download Rule/SMTP Rule processors act just like the built in Download Rule/SMTP Rule processors, but can be more powerful
Message Processors act on all messages (incoming, outgoing and local) and can redirect them, modify them etc
Password Checkers allow 'password quality' checkers to be implemented - eg a password checker could check that a user's password contains numbers and letters, etc
You cannot replace VPOP3 plugins whilst VPOP3 is running and has the plugins loaded, so to remove or replace an existing plugin, you should Unload All Plugins first. The Refresh Plugin List button makes VPOP3 scan the Plugins directory for any new plugins, so this will make it reload any previously 'unloaded' plugins as well as load any newly installed plugins.
Some plugins support access to their configuration through the VPOP3 settings. In that case, click on the plugin name to access the plugin's settings.
