Sendmux

Build AI-powered applications with an email infrastructure platform designed for autonomous agents. Sendmux provides dedicated mailboxes, unified email APIs, intelligent routing, and provider-independent delivery, making it easy for AI agents to send, receive, and manage email through one developer-friendly interface.

Give Every AI Agent Its Own Email Inbox

Create dedicated mailboxes for AI agents, process inbound email as structured data, and send messages through your preferred email providers without managing separate email systems.

Whether you're building AI assistants, customer support agents, workflow automation, or multi-agent platforms, Sendmux simplifies email communication through one unified API.

Key Features

Dedicated AI Agent Mailboxes

Assign every AI agent its own email identity.

Create mailboxes using:

• Verified custom domains
• Shared agent domains
• Individual inboxes
• Team-specific mailboxes
• Multi-tenant deployments

for organized email management.

Structured Email Processing

Make inbound email easier for AI models to understand.

Receive messages as:

• Clean JSON
• Parsed message bodies
• Attachment metadata
• Email headers
• Link information

with signatures and quoted replies removed automatically.

Unified Email Sending API

Send email through HTTP or SMTP using the same mailbox.

Support includes:

• Plain text
• HTML emails
• Attachments
• Custom headers
• Idempotent retries

for reliable outbound delivery.

Flexible Provider Routing

Keep control over email delivery infrastructure.

Route messages through:

• Gmail
• SendGrid
• Mailgun
• Resend
• SMTP providers

using weighted routing, delivery groups, and automatic failover.

Events & Synchronization

Keep applications updated as mailbox activity changes.

Integration options include:

• Signed webhooks
• Server-Sent Events (SSE)
• Typed polling
• Mailbox events
• Real-time synchronization

for responsive workflows.

Multi-Tenant Infrastructure

Scale email across customers and AI agents securely.

Features include:

• Team isolation
• Inbox-scoped API keys
• Bulk mailbox management
• Labels and threads
• Customer-specific routing

for SaaS and enterprise platforms.

Built for AI-Native Email Workflows

Sendmux helps developers build AI applications that can reliably send, receive, organize, and process email without maintaining separate inbox, parsing, and delivery systems.

Key benefits include:

• Unified email API
• AI-ready email parsing
• Dedicated agent mailboxes
• Intelligent provider routing
• Multi-tenant email infrastructure

Built For

• AI Developers
• SaaS Companies
• Agent Platform Builders
• Automation Teams
• Enterprise Engineering Teams
• Product Developers

Common Use Cases

• AI agent email
• Customer support automation
• Workflow automation
• Multi-agent communication
• Email-enabled AI products
• Multi-tenant email infrastructure

Why It Matters

Building AI systems that interact with email often requires combining mailbox hosting, email parsing, delivery providers, routing logic, retries, and event handling from multiple services. Sendmux brings these capabilities together into one platform by providing dedicated agent mailboxes, structured email parsing, unified sending APIs, intelligent provider routing, and scalable multi-tenant infrastructure. Developers can focus on building AI workflows while keeping email management reliable, flexible, and easy to scale.

Power AI Agents With Native Email

Create dedicated mailboxes, process structured email, route messages through your preferred providers, and build scalable AI-powered email workflows with a unified email API designed for autonomous agents.