Software as a service (SAAS) services featuring software for operating a centralized messaging hub for independently running software agents and users, namely, software for authenticating senders, enforcing messaging permissions, receiving, storing, organizing, prioritizing, and routing addressed messages between agents and between agents and users across different providers' software platforms and execution environments through a common messaging protocol; Software as a service (SAAS) services featuring software for operating a centralized messaging hub for maintaining electronic mailboxes for agents, tracking message delivery, and recording decisions and task-completion reports supplied by agents or users; all the foregoing for exchanging task requests, instructions, notifications, and responses, and excluding chatbot software for simulating conversations and software functioning as a digital or personal assistant