Marshmellos

Email infrastructure you control.

Send transactional email with a transparent API, reusable templates, and full delivery visibility.

Event timeline

  • Email sent
  • Delivered → gmail.com
  • Opened → gmail.com
  • Clicked → verify link
  • Webhook triggered

Built for developers and teams building modern products.

Product capabilities

What you get. No hype.

  • Sending API

    Ship transactional email from your app with one call. Every message and event is visible—no black box.

  • Domain verification

    Get mail delivered and trusted. We guide you through DNS records so your domain authenticates correctly.

  • Templates

    Create consistent emails with reusable templates and dynamic variables—verification, reset, and notifications.

  • Event timeline

    Know what happened to each email. Delivered, opened, clicked, bounced—so you can fix issues quickly.

Everything you need to ship

Templates, domains, webhooks, and real-time events. Built for teams that move fast.

Dynamic Templates

Build once, personalize infinitely. Use variables like {{name}} and {{company}} to create emails that feel personal at scale.

Domain Authentication

SPF, DKIM, DMARC—configured in minutes. Your emails land in inboxes, not spam folders. We guide you through every step.

Webhooks

Get notified instantly when emails are delivered, opened, clicked, or bounced. Keep your app in sync with what actually happened.

See every email event

Event timeline
  • Verification email sent
  • Delivered → gmail.com
  • Opened → gmail.com
  • Clicked → verify link
  • Webhook triggered

No black box. Every email event is visible.

Send email in seconds

One call. Template or raw content. Full visibility.

await marshmellos.send({
  to: "[email protected]",
  template: "welcome"
})

One API key, template or raw content. Events and webhooks keep your app in sync with what actually happened.

How it works

From signup to first send.

  1. Create account

    Sign up with Google, Apple, or work email.

  2. Verify domain

    Authenticate your sending domain with DNS records.

  3. Connect API

    Generate your API key and integrate your app.

  4. Send email

    Deliver transactional emails with full visibility.

Email infrastructure is fragmented; we built Marshmellos to offer a clear product layer—designed for clarity and control.

Why we exist →

Built in the open

See what's live today and what we're building next.

View roadmap

How Marshmellos compares

Different tools serve different needs. See how we fit alongside other email platforms.

Compare platforms

Start sending email with clarity