The email API that shows its work.

Send transactional and marketing email with one call, then watch every message move from request to inbox — with automatic provider failover, deliverability guardrails, and EU-first data residency built in.

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Free plan includes 3,000 emails a month. No credit card required.

import { Irisend } from "irisend";

const irisend = new Irisend(process.env.IRISEND_API_KEY);

const { id } = await irisend.emails.send({
  from: "Acme <hello@acme.dev>",
  to: "delivered@acme.dev",
  subject: "Welcome to Acme",
  html: "<strong>It just works.</strong>",
});

{ "id": "em_9f2K3mQ1zPr7vT6yB4wL0nC" }

email.queued
email.sent
email.delivered

Trusted by product and platform teams shipping every kind of email

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Built for the parts of email that break in production.

Everything you need to send with confidence — deliverability guardrails, real event data, and infrastructure that doesn't depend on a single provider staying up.

Reputation circuit breaker

Sending pauses automatically when a domain's bounce or complaint rate crosses a threshold, so one bad list can't sink the rest of your account.

Every event, one endpoint

Standard Webhooks–compatible signatures for sent, delivered, bounced, opened, and clicked, with per-attempt logs and one-click replay.

Verify a domain in minutes

DKIM, SPF, and DMARC records are generated for you, with live per-record verification status instead of a wall of raw DNS.

Send now, later, or a hundred at once

Schedule up to 30 days out or send up to 100 personalized emails in a single batch call, with idempotency keys on both.

React Email compatible

Render your existing React Email components straight to HTML — switching providers doesn't mean rewriting templates.

Data that stays in the EU

Opt-in EU-only data residency, a published subprocessor list, and a Data Processing Agreement written to be read, not just signed.

Never go down with one provider

If your primary sending provider degrades or throttles, Irisend reroutes automatically and emits a provider.failover event.

Guardrails for AI agents, not raw keys

An MCP server with diagnostic and rate-limited send tools, built for Claude Code, Cursor, and other agents that send on your behalf.

Stop faking a mailbox in Slack

Test-mode keys capture sends into a local dev inbox with hot-reloading previews, instead of routing test mail to real inboxes.

Agent-ready, not just developer-friendly.

Irisend ships an MCP server built for autonomous coding agents — the same operating model we use to build Irisend itself — with diagnostics and guardrails an agent can act on without waiting for a human.

Diagnostic tools: check_domain_health, explain_bounce, and spam_score give an agent self-serve answers instead of paging you.
Guardrailed sending: Rate limits, content-policy checks, and domain scoping are enforced server-side — not left to the agent's judgment.
Optional human approval: Route a send_email call through a Slack or webhook approval step before anything actually goes out.
Works with your existing agent: Claude Code, Cursor, and any MCP-compatible client connect with one config block — no custom integration.

agent-safe-send.tsTypeScript

// an agent calls the guardrailed tool
await mcp.call("send_email", {
  to: "user@example.com",
  subject: "Reset your password",
});

// Irisend enforces policy before sending
// -> rate limit: 4 / 10 per minute
// -> content policy: passed
// -> domain: verified
// sent as em_9f2K3mQ1zPr7vT6yB4wL0nC

Watch your reputation, not just your inbox.

Every domain gets a health score built from bounce rate, complaint rate, and DNS drift, with alerts before a problem turns into paused sending. Bounce and complaint rates render per ISP, not as a single aggregate number.

Proactive alerts on Slack, email, or webhook before sending is paused
A pre-send checker flags SPF/DKIM issues and broken links before you hit send
Domain, key, and workspace-level views — not one dashboard for everything

Pricing that scales with your sending, not your headcount.

Start free, upgrade when you need more volume. Every plan includes the full API, event webhooks, and deliverability guardrails — no feature gating on the essentials.