Abstract: An organization that wishes its messages to be secure (the “communicating organization”) uses services of a secure communications infrastructure to securely exchange communications among its users. The secure communications infrastructure allows granting to third-party applications the permission to act on behalf of the users when using the secure communications infrastructure. This delegation may be accomplished at a very granular level, specifying the particular applications that are authorized to act on behalf of a user, the particular operations that those applications are authorized to perform, and/or in which contexts the applications may perform the operations. An agent component acts as an intermediary between third-party applications and the core of the secure communications infrastructure. This permits the third-party application to take actions on behalf of the user, while also preventing the third-party applications from obtaining the security-specific data that could lead to a breach of security.