You can add new commands to the client's menus or toolbar, or completely replace the behavior of existing commands and toolbar buttons. Adding commands allows you to customize in several ways. For example:
Custom spelling and grammar tools can be added to the Microsoft Exchange menu. If a user has composed a message, choosing a custom Spelling or Grammar command could invoke an ISV-supplied spell-checker or grammar-checker. It is also possible to add a thesaurus, text formatting tools, and other functionality provided by many word processors.
When a specific public folder has the focus, menu items or toolbar buttons can be enabled that are specific to that folder. For example, if the public folder is associated with an on-line service, you might want to include a Retrieve Latest command that prompts the on-line service to download the most current information into the selected topic area of the public folder.
When messages of a specific class are selected, new application behavior can be added to handle messages of that class in a specific way. For example, you might want to replace the default behavior of the Microsoft Exchange Delete command when a message of a specific class is selected. The new behavior might simply move the message into a certain folder where it is processed at a later time.