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Sendmux Pricing 2026

Complete pricing guide for Sendmux — plans, costs, and free options.

PaidStarting at $0.15Updated October 29, 2026

💰 Sendmux Pricing Overview

Sendmux uses a paid pricing model. Requires a paid subscription or one-time purchase. Current pricing: Usage-based with no subscription and free to start. Sending or receiving through your own providers is $0.15 per 1,000 emails; the managed Amazon SES route is $0.25 per 1,000; mailbox storage is $0.02 per GB per month. Seats, mailboxes, and tiers are not metered. The vendor's worked example: 1,000,000 standard sends bills at $150/month. Enterprise adds dedicated infrastructure and priority support. Sendmux is an ai agent infrastructure tool known for email api with real agent inboxes, sse delivery, and multi-provider routing — mcp, cli, sdk, and langchain support. You can get started with Sendmux for free and upgrade to a paid plan as your needs grow.

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🔍 Compare Before You Buy

Comparing Sendmux to similar tools helps you make the best choice for your budget and needs:

Resend

Freemium

Developer-focused email API with React templates

Free plan + paid from $20/month

Compare with Sendmux →

Sendmux Plans & Pricing

Most Popular

Sending or receiving through your own providers is

$0.15

Per 1,000 emails

the managed Amazon SES route is

$0.25

Per 1,000

mailbox storage is

$0.02

Per GB per month

The vendor's worked example: 1,000,000 standard sends bills at

$150/month

Enterprise

Custom

Adds dedicated infrastructure and priority support

* Pricing information is based on publicly available data and may not reflect current promotions, annual discounts, or regional pricing. Visit the official Sendmux website for the latest pricing.

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Is Sendmux Free?

✓Yes, Sendmux offers a free plan

Usage-based with no subscription and free to start. Sending or receiving through your own providers is $0.15 per 1,000 emails; the managed Amazon SES route is $0.25 per 1,000; mailbox storage is $0.02 per GB per month. Seats, mailboxes, and tiers are not metered. The vendor's worked example: 1,000,000 standard sends bills at $150/month. Enterprise adds dedicated infrastructure and priority support.

Check Sendmux pricing at the source

The breakdown above is our summary of Sendmux's published pricing, not a quote. Plans, limits and what each tier includes change without notice — confirm on Sendmux's own pages before you buy.

Official Sendmux site ↗

We do not represent Sendmux and these links are not paid placements.

Is Sendmux Worth It?

Sendmux is a premium ai agent infrastructure tool that offers 6 key features including Real per-agent inboxes with server-sent-event delivery, no polling, Multi-provider routing with quotas, weighted delivery, and failover, Hosted MCP endpoint with OAuth and scoped grants. Sendmux is an email API built specifically for AI agents, which in practice means it solves the receiving half that transactional email providers largely ignore. You create a real mailbox for an agent, then send through your own providers and receive over server-sent events rather than polling — the SDK exposes a `streamMailboxEvents` async iterator that yields `message.received` events as they arrive. The routing layer is the other half: quotas, weighted delivery across multiple providers, and failover, configured through one API instead of per-provider glue. Integration surface is deliberately broad for agent stacks. There is a hosted MCP endpoint at mcp.sendmux.ai with OAuth and scoped grants, an installable skills package via `npx skills add Sendmux/skills`, a global CLI (`@sendmux/cli`) with a `mailbox:stream-events --follow` command that emits one JSON object per line, TypeScript and Python SDKs, a LangChain toolkit exposing send_email, list_messages, and reply as agent tools, and a Vercel AI SDK adapter. The site publishes an llms.txt and an auth.md written for agents to read and self-onboard from. Idempotency keys are supported on sends. Usage is metered per email with a live dashboard showing sends and spend, and the vendor is explicit that seats, mailboxes, and tiers are not metered — only volume is.

✅ Sendmux is a good choice if you need:

  • •Real per-agent inboxes with server-sent-event delivery, no polling
  • •Multi-provider routing with quotas, weighted delivery, and failover
  • •Hosted MCP endpoint with OAuth and scoped grants
  • •TypeScript and Python SDKs, a CLI, LangChain toolkit, and Vercel AI SDK adapter
  • •Installable agent skills package and an agent-readable llms.txt / auth.md

💡 Value Assessment

With a free tier available, Sendmux is an easy recommendation for anyone looking to try ai agent infrastructure tools without financial commitment. The paid plans offer good value for power users who need the additional features and higher usage limits.

Sendmux Key Features

Sendmux comes packed with features that make it a strong contender in the ai agent infrastructure space. Here's what you get:

1.
Real per-agent inboxes with server-sent-event delivery, no polling

Real per-agent inboxes with server-sent-event delivery, no polling helps you work more efficiently with Sendmux.

2.
Multi-provider routing with quotas, weighted delivery, and failover

Multi-provider routing with quotas, weighted delivery, and failover helps you work more efficiently with Sendmux.

3.
Hosted MCP endpoint with OAuth and scoped grants

Hosted MCP endpoint with OAuth and scoped grants helps you work more efficiently with Sendmux.

4.
TypeScript and Python SDKs, a CLI, LangChain toolkit, and Vercel AI SDK adapter

TypeScript and Python SDKs, a CLI, LangChain toolkit, and Vercel AI SDK adapter helps you work more efficiently with Sendmux.

5.
Installable agent skills package and an agent-readable llms.txt / auth.md

Installable agent skills package and an agent-readable llms.txt / auth.md helps you work more efficiently with Sendmux.

6.
Idempotency keys on sends and a live per-account usage meter

Idempotency keys on sends and a live per-account usage meter helps you work more efficiently with Sendmux.

Sendmux Alternatives & Their Pricing

Considering alternatives to Sendmux? Here's how competing tools compare on pricing:

Resend

Freemium

Developer-focused email API with React templates

Pricing: Free tier (3000 emails/mo). Pro $20/mo, Scale $90/mo, Enterprise custom

Ready to try Sendmux?

Visit the official website for the latest pricing and to get started.

Frequently Asked Questions

Is Sendmux free to use?

Yes, Sendmux offers a free tier that you can use without paying. Paid plans starting at $0.15 unlock additional features and higher usage limits.

How much does Sendmux cost in 2026?

As of 2026, Sendmux pricing is: Usage-based with no subscription and free to start. Sending or receiving through your own providers is $0.15 per 1,000 emails; the managed Amazon SES route is $0.25 per 1,000; mailbox storage is $0.02 per GB per month. Seats, mailboxes, and tiers are not metered. The vendor's worked example: 1,000,000 standard sends bills at $150/month. Enterprise adds dedicated infrastructure and priority support. Visit the official Sendmux website for the most current pricing.

What is the cheapest Sendmux plan?

The cheapest option is the free tier. If you need premium features, the most affordable paid plan is Sending or receiving through your own providers is at $0.15.

Does Sendmux offer enterprise pricing?

Yes, Sendmux lists an enterprise or custom-priced plan. Contact their sales team for a quote.

What are the best alternatives to Sendmux?

Popular alternatives to Sendmux include Resend. Each offers different features and pricing structures. Compare them on AISO Tools to find the best fit for your needs and budget.

Is Sendmux worth the price?

Sendmux offers features like Real per-agent inboxes with server-sent-event delivery, no polling, Multi-provider routing with quotas, weighted delivery, and failover, Hosted MCP endpoint with OAuth and scoped grants. Whether it's worth the investment depends on your specific needs, usage volume, and budget. The free tier lets you try it before committing to a paid plan.

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