Plesk provides a mechanism that allows administrators to track specific Plesk events and make Plesk execute custom scripts when these events occur. The events include operations that Plesk users perform on accounts, subscriptions, websites, service plans, and various Plesk settings.
It works the following way: you create a script to be executed upon a certain Plesk event, and then set up an event handler in Server Administration Panel that triggers processing of the event by the script. You can assign several handlers to a single event.
To learn how to track Plesk events and set up execution of commands or custom scripts, refer to the Administrator's Guide, chapter Event Tracking.