EmailSender With Nodemailer

You need to add the nodemailer package to the project. From a Terminal window opened in the project folder, execute the npm CLI (Node Package Manager Command Line Interface) install command.

npm install nodemailer

This configuration requires an existing SMTP server. Many hosting services offer a SMTP server with a domain name registration. Other services like Amazon SES (SES), SendGrid, or Mailgun offer SMTP servers. If you have an SMTP server, use the .env file to pass the SMTP configuration to the application's process.env object.

.env

SMTP_CONFIGURED=true
SMTP_HOST=smtp.example.com
SMTP_PORT=587
SMTP_SECURE=false
SMTP_AUTH_USER=support@example.com
SMTP_AUTH_PASSWORD=P@ssword
SMTP_ADMIN_EMAIL=admin@example.com

Add a new root directory named Utilities and add a new file named email-sender.mjs. Import nodemailer.

email-sender.mjs

import nodemailer from 'nodemailer';

const EmailSender = {};

// Transporter configuration
const transporter = nodemailer.createTransport({
  host: process.env.SMTP_HOST,
  port: process.env.SMTP_PORT,
  secure: process.env.SMTP_SECURE === 'true',
  auth: {
    user: process.env.SMTP_AUTH_USER,
    pass: process.env.SMTP_AUTH_PASSWORD,
  },
});

EmailSender.verify = async () => {
  try {
    await transporter.verify();
    console.log("The Transporter verified successfully.");
    return { success: true };
  } catch (error) {
    console.error("Verification failed", error);
    return { success: false };
  }
};

EmailSender.send = async (mailOptions) => {
  try {
    const info = await transporter.sendMail(mailOptions);
    console.log('Message sent: %s', info.messageId);
    return { success: true, info: info };
  } catch (error) {
    console.error('Error sending email:', error.message);
    return { success: false, error: error.message };
  }
};

export default EmailSender;

The Get Started App has a contact us form in a modal complete with client-side validation. If SMTP_CONFIGURED=true the modal is enabled.

The modal posts the form data to a contact-us route. You need to configure a mailOptions parameter to pass to the EmailSender.send function. The mailOptions include a text formatted and a html formatted message. The Get Started App has an InputValidator module for server-side validation. The Get Started App also has a Formatter module with a getContactUsTemplate function which provides a HTML formatted message.

Import the EmailSender.

import EmailSender from '../utilities/email-sender.mjs';

Validate client form inputs, configure the mailOptions, and send both text and html messages with the EmailSender.

const { email, subject, message, verifyhuman } = req.body;

if (parseInt(verifyhuman) != 2) throw new Error("Human verification failed.");
let validatorResult = InputValidator.emailAddress(email);
if (!validatorResult.valid) throw new Error("Email validation failed.");
if (subject.length < 8 || subject.length > 100) throw new Error("Subject length validation failed.");
validatorResult = InputValidator.containsHTML(subject);
if (!validatorResult.valid) throw new Error("Subject validation failed.");
if (message.length < 20 || message.length > 500) throw new Error("Message length validation failed.");
validatorResult = InputValidator.containsHTML(message);
if (!validatorResult.valid) throw new Error("Message validation failed.");

const contaxtUsSubject = 'New Contact from Get Started App';
const textMessage = `Contact's Email: ${email}\nContact's Subject: ${subject}\nContact's Message:\n${message}`;
const htmlMessage = Formatter.getContactUsTemplate(contaxtUsSubject, email, subject, message);

const mailOptions = {
    from: process.env.SMTP_AUTH_USER, // The authorized sender email address
    to: process.env.SMTP_ADMIN_EMAIL, // The administrator email address you want to receive emails
    subject: contaxtUsSubject,
    text: textMessage,
    html: htmlMessage
};

const senderResult = await EmailSender.send(mailOptions);
if (senderResult != null && senderResult.success) {
    console.log("Email sent: ", senderResult.info.response);
    return res.status(201).redirect('/about?statusalert=Email sent. We will respond ASAP.');
} else {
    let error = "Error: result is null.";
    if (senderResult != null) { error = "Error: " + senderResult.error; }
    console.error(error);
    return res.status(201).redirect('/about?statusalert=Error: There was a problem sending the email.');
}