Sendmux

Sendmux gives developers a straightforward way to give AI agents a real email identity. Instead of stitching together a sending API, a mailbox provider, a parser, a webhook layer, and a separate billing system, teams get one platform that covers inbound mailboxes, outbound sending, routing, quotas, webhooks, and live inbox events from day one.

Your agents can receive email in dedicated mailboxes, read messages and full threads, process attachments, send replies, and stream inbox activity in real time through Server-Sent Events. That means an agent can react to an incoming support request or a customer reply the moment it lands, without polling or fragile glue code.

On the outbound side, Sendmux supports SMTP, Gmail OAuth, Outlook OAuth, and Sendmux-managed Amazon SES. Delivery groups, weighted routing, per-provider quotas, health checks, and failover keep messages flowing even when a single provider runs into trouble.

Sendmux is built for AI agent teams, automation agencies, SaaS platforms, and developers creating support agents, sales agents, scheduling agents, monitoring agents, and workflow agents. It also ships with REST APIs, OpenAPI specs, SDKs, a CLI, MCP tools, and Sendmux Skills, so integrating email into your agents fits naturally into the way you already build.