How to send email from Express

To send email from an Express app, the usual approach is to use Nodemailer.

1) Install Nodemailer

npm install nodemailer

2) Create a mail transporter

Example with Gmail SMTP:

const nodemailer = require("nodemailer");

const transporter = nodemailer.createTransport({
  service: "gmail",
  auth: {
    user: process.env.EMAIL_USER,
    pass: process.env.EMAIL_PASS, // use an App Password for Gmail
  },
});

3) Send an email in an Express route

const express = require("express");
const nodemailer = require("nodemailer");
require("dotenv").config();

const app = express();
app.use(express.json());

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

app.post("/send-email", async (req, res) => {
  try {
    const { to, subject, text } = req.body;

    const info = await transporter.sendMail({
      from: process.env.EMAIL_USER,
      to,
      subject,
      text,
    });

    res.json({ message: "Email sent", id: info.messageId });
  } catch (error) {
    console.error(error);
    res.status(500).json({ message: "Failed to send email" });
  }
});

app.listen(3000, () => console.log("Server running on port 3000"));

4) Add environment variables

Create a .env file:

EMAIL_USER=your-email@gmail.com
EMAIL_PASS=your-app-password

5) Test the endpoint

Send a POST request to /send-email:

{
  "to": "someone@example.com",
  "subject": "Hello",
  "text": "This is a test email"
}

Notes

• For Gmail, you usually need an App Password if 2FA is enabled.
• For production, use a proper email service like:
  • SendGrid
  • Mailgun
  • Amazon SES
  • Postmark

If you want, I can also show:

1. sending HTML emails, or
2. a complete Express + Nodemailer example with attachments.