How do I send an email when something happens in my app?

The usual approach is:

1. Detect the event in your app
   Example: user signs up, order is placed, password reset is requested.

2. Trigger a backend action
   Don’t send email directly from the frontend. Call your server or a background job.

3. Use an email service/provider
   Common options:

   • SendGrid
   • Mailgun
   • Amazon SES
   • Postmark
   • Resend

4. Send the email from the backend Your backend prepares the recipient, subject, and body, then calls the email provider’s API.

5. Do it asynchronously if possible For reliability, queue the email in a background worker so the app doesn’t wait on the send.

Example flow

• User places an order
• Your app writes the order to the database
• Your backend emits an order_created event
• A worker listens for that event
• Worker sends an email confirmation

Very small example in Node.js

import nodemailer from "nodemailer";

const transporter = nodemailer.createTransport({
  service: "gmail",
  auth: {
    user: process.env.EMAIL_USER,
    pass: process.env.EMAIL_PASS,
  },
});

await transporter.sendMail({
  from: "yourapp@example.com",
  to: "user@example.com",
  subject: "Welcome!",
  text: "Thanks for signing up.",
});

Important notes

• Use environment variables for credentials.
• Add rate limiting / retries.
• Consider HTML templates for better-looking emails.
• Make sure your provider is configured for SPF/DKIM/DMARC to improve deliverability.

If you want, I can show you:

• how to do this in Python / Node / PHP / Ruby
• how to set it up with SendGrid / SES / Resend
• how to trigger emails from a database event or webhook