Regulating an extensibility point's access to a wrapped e-mail message

摘要

Prior to sending a message to an extensibility point, the message is wrapped with a wrapper object associated with the extensibility point. The wrapper object can be validated by the extensibility point when the extensibility point is ready to commence its operation on the message. Validation of the wrapper object enables the extensibility point to access the message. The wrapper object can later be invalidated by the extensibility point when the extensibility point has completed its operation on the message. Invalidation of the wrapper object denies the extensibility point access to the message.