Sendmux

What is Sendmux?

Sendmux is an email platform built for AI agents and the products around them. It gives each agent its own inbox, routes outbound mail through providers you already use, and fails over automatically when one provider struggles. Everything returns as clean structured data instead of messy raw email.

Top Features:

• Agent inboxes: each agent gets a dedicated mailbox with clean JSON formatted messages.
• Provider routing: connect Gmail, SendGrid, Mailgun, or SMTP and split traffic by weight.
• Automatic failover: health checks disable a failing provider without any manual work needed.
• Live events: webhooks and server-sent events push mailbox updates the moment they happen.

Use Cases:

• Agent communication: let AI agents send and read email through their own addresses.
• Transactional mail: route product notifications through several providers for better delivery rates.
• Platform building: give every customer their own isolated inboxes with team-scoped API keys.

Who Can Use Sendmux?

• AI builders: developers adding email abilities to autonomous agents and assistants they create.
• SaaS teams: product engineers who need reliable sending across multiple email providers.
• Platform founders: startups giving email features to many tenants under one account.

Pricing

• Free tier ($0): start with fifty emails per day and no credit card.
• Standard ($0.15 per 1,000): pay only for outbound and inbound mail you actually use.
• Managed SES ($0.25 per 1,000): send through a built-in Amazon SES route with no extra setup.
• Enterprise (custom): dedicated infrastructure, priority support, and volume discounts for large senders.

Pros and Cons

Pros:

• Usage pricing: you pay only for what you send with no seat fees.
• Provider freedom: bring your own senders and switch between them whenever you want.
• Agent ready: structured JSON cuts the tokens your language models read drastically.

Cons:

• Developer focus: the API design suits coders more than non-technical email users.
• Setup needed: connecting your own providers takes more work than a closed system.
• New service: a young platform still proving reliability at very large scale.

FAQs:

1) What is Sendmux used for?

It gives AI agents and apps email inboxes plus reliable outbound mail routing.

2) Is there a free plan?

Yes, every team starts free with fifty emails a day and no card.

3) Can I use my own provider?

Yes, you can route mail through Gmail, SendGrid, Mailgun, Resend, or SMTP.

4) Does it support MCP?

Yes, it includes MCP support plus SDKs for several popular programming languages.

5) How is pricing calculated?

You pay per thousand emails sent or received, plus small monthly storage costs.