Sendmux

Sendmux is email infrastructure for AI agents and modern apps: one API to send, receive, route, and monitor email. Most providers only send. Sendmux gives your agent a real inbox that can send transactional email, receive replies, hold and triage messages, and respond, all in one place. The difference is safety. An agent self-registers for its own constrained mailbox and can read and receive straight away, but it cannot send until you, the human owner, approve it. So you can give an agent its own email address without risking your sending reputation. Connect through a REST API, CLI, hosted MCP server with OAuth, or SDKs for Python, Go, Ruby, PHP, and TypeScript. Use your own verified domain or the shared myagent.mx domain to test in minutes. Searchable delivery logs, exportable metrics, signed webhooks, and scoped API keys keep production email observable and secure. Give your agent an inbox, keep a human in the loop on every send, and see exactly what went out.