Sendmux

About

Sendmux is an email inbox API for AI agents that lets developers give agents real mailboxes, controlled outbound sending, live inbox events, and developer tools in one platform. Instead of stitching together a sending API, mailbox provider, parser, webhook service, and separate billing system, teams can use Sendmux as the email API layer for agents that need to send, receive, route, and react to email in production. Sendmux is built for developers and AI product teams. It provides Management, Sending, and Mailbox APIs, OpenAPI specs, webhooks, Server-Sent Events, SMTP, IMAP, SDKs for TypeScript, Python, Go, PHP, and Ruby, the sendmux CLI, MCP tools, and Sendmux Skills for agent workflows.