Programming Tips and Suggestions

When writing an extension, you can reduce the number of bugs and other problems by observing the following:

• Pointers can become invalid shortly after they are used within the scope of a single function. Do not store pointers to callback functions for later use outside of the current function. The same advice applies for pointers returned from callback functions.
• Creative use of the hMenu or hWnd pointers may cause problems in future versions of Microsoft Exchange. Avoid performing special “tricks” with these pointers.
• Avoid adding menus to Microsoft Exchange outside the scope of the IExchExtCommands::InstallCommands method.
• When adding menu commands for your provider extension, place these menu commands underneath the Find command on the Tools menu.
• When adding your provider-specific Help command, place it underneath the Microsoft Exchange Help Topics command on the Help menu.