Extension plug-ins for processing messages
You can add extension plug-ins to a BlackBerry Messaging Agent. The BlackBerry Messaging Agent uses extension plug-ins to process and make changes to email messages and attachments that the BlackBerry Messaging Agent sends to and receives from BlackBerry devices. For example, you can add an extension plug-in to modify the signature in email messages.
Before you add an extension plug-in to the BlackBerry Administration Service, you must install the extension plug-in application on the computer the hosts the BlackBerry Enterprise Server. By default, each BlackBerry Messaging Agent in your organization's BlackBerry Domain includes the extension plug-in BBAttachBESExtension, which connects the BlackBerry Messaging Agent to the BlackBerry Attachment Service so that the BlackBerry Attachment Service can process email message attachments. If you add multiple extension plug-ins to a BlackBerry Messaging Agent, you can define the order that the BlackBerry Messaging Agent uses the extension plug-ins to process email messages in.