Introduction
Expand Quick Start
Expand Extension Structure
 Extensions Management Utility
 Retrieving User and Domain Data
 XML API
 Command-Line Interface
 List Group Operations Support
 The Key-Value Storage
Expand Event Handlers
 Scheduled Tasks
 File Manager
 Retrieving Plesk License Information
 Default Column for Sorting
 Rendering UI Elements
 Plesk Home Page Widgets
 Global JavaScript and CSS Files
 Content Include Hook
 Authentication Hook
 Custom Buttons
 Localization
 Testing Extensions
Collapse Mail Handlers
    Hooking Points
   Expand Handler Calling Conventions
   Collapse Managing Handlers
       Registering Mail Handlers
       Viewing Mail Handlers
       Removing Mail Handlers
       Disabling/Enabling Mail Handlers
    Implementation Notes
 Integration with Third-Party DNS Services
 Setting Up a Slave DNS Server
 Extension Examples