Stack0
Use Cases/Email

Greet every new user instantly

Send personalized welcome emails the moment users sign up. Templates, sequences, and full delivery tracking in one API call.

Instant DeliveryPersonalizationSequencesAnalytics
Send Your First Welcome EmailView Docs
import { Stack0 } from '@stack0/sdk'
 
const stack0 = new Stack0({ apiKey: process.env.STACK0_API_KEY })
 
// Send welcome email on user signup
export async function sendWelcomeEmail(user: User) {
  await stack0.mail.send({
    from: 'hello@yourdomain.com',
    to: user.email,
    subject: `Welcome to our app, ${user.name}!`,
    templateId: 'welcome-email',
    templateVariables: {
      name: user.name,
      loginUrl: 'https://app.yourdomain.com/login',
      supportEmail: 'support@yourdomain.com',
    },
  })
}
 
// Or trigger a welcome sequence
export async function triggerWelcomeSequence(user: User) {
  await stack0.mail.events.track({
    eventName: 'user_signed_up',
    contactEmail: user.email,
    properties: {
      name: user.name,
      plan: user.plan,
    },
  })
}

Features

What's included

Template Variables

Use {{name}}, {{company}}, or any variable in your templates. Preview with test data.

Fast Delivery

Sub-second sending for time-critical emails. Users get their welcome email instantly.

Open & Click Tracking

Know who engages with your welcome emails. Identify users who need follow-up.

Bounce Handling

Invalid emails automatically suppressed. Keep your sender reputation clean.

Sequences

Build multi-step onboarding flows. Day 1 welcome, Day 3 tips, Day 7 check-in.

Audiences

Segment users by signup date, plan, or custom properties for targeted messaging.

Why Stack0

Built for production

Instant delivery

Welcome emails sent within seconds of signup. No delays that leave users waiting.

Personalization built in

Use template variables for names, company info, and custom data. Make every email feel personal.

Track engagement

See who opens your welcome emails. Identify users who might need extra onboarding help.

Welcome sequences

Extend beyond the first email. Build multi-step onboarding sequences triggered by events.

TypeScript SDK

Full type safety means fewer bugs. Your IDE catches errors before users do.

Simple pricing

$0.50 per 1,000 emails. No monthly minimum. Start with $5 free credits.

Applications

Common implementations

SaaS Onboarding

Welcome new trial users with getting-started guides and key feature highlights.

E-commerce Registration

Greet new customers with welcome discounts and product recommendations.

Newsletter Signup

Confirm subscriptions and set expectations for what subscribers will receive.

App Install

Welcome mobile app users with setup tips and feature walkthroughs.

FAQ

Frequently asked questions

Welcome emails are sent within 1-3 seconds of your API call. We prioritize transactional emails to ensure users receive confirmation immediately after signing up.

Yes. Use the events API to trigger automated sequences. For example, send a welcome email on Day 1, a tips email on Day 3, and a check-in on Day 7. Sequences are configured in your dashboard.

Use template variables like {{name}}, {{company}}, or any custom data. Variables are replaced when the email is sent. You can preview emails with test data before going live.

Hard bounces are automatically detected and the email address is suppressed from future sends. You can view bounce events in your dashboard or receive webhooks for real-time notification.

Yes. Open and click tracking are enabled by default. Use this data to identify users who might need extra onboarding help or to measure the effectiveness of your welcome content.

Ready to build?

Plans start at $5/month.

Get Started