Sendmux — Email API for AI Agents provides a unified, AI-first email layer that lets developers create dedicated agent inboxes, send through your own providers with weighted routing, quotas and automatic failover, and receive inbound mail as compact structured JSON (drastically cutting LLM token waste); it exposes webhooks, SSE and MCP integrations for live agent workflows, scoped API keys and multi‑tenant controls, and centralized logs so AI agents can reliably read, act on, and send email without building complex provider glue.