Learning Nodejs # 10: How to send an email at Nodejs?

Pay attention.

There are several applications or services that you use and those services often send emails.

Some even reach your mailbox.

Example:

When you rarely open Facebook, Facebook will send an email.

When you register for a service, you will receive an email from the service.

Do they send manually?

The answer: No .

Who will be able to send emails to thousands or millions of users?

Can you afford it?

Yes, able to use the program.

This program is what we will make in this tutorial.

Email sending programs are usually needed for some case studies such as:

• Reset Password;
• Email Marketing;
• Contact Form;
• Account Verification;
• etc.

In this tutorial, we will learn how to send email at nodejs using modules nodemailerand services gmail.

Let's start…

Initial Preparation

Please create a new project by creating a directory named  nodejs-email.

mkdir nodejs-email && cd nodejs-email

Then install it nodemailerthere.

npm install nodemailer

Wait until the installation process is complete.

Make the Nodejs Program to Send Email

Please create a new file named  send_email.js, then fill in the following code:

var nodemailer = require('nodemailer');

var transporter = nodemailer.createTransport({
    service: 'gmail',
    auth: {
        user: 'youremail@gmail.com',
        pass: 'your password'
    }
});

var mailOptions = {
    from: 'youremail@gmail.com',
    to: 'yourfriend@gmail.com',
    subject: 'Sending Email using Nodejs',
    text: 'That was easy!'
};

transporter.sendMail(mailOptions, (err, info) => {
    if (err) throw err;
    console.log('Email sent: ' + info.response);
});

Explanation:

First, we need a module nodemailer. Then we import with functions reqiuire().

var nodemailer = require('nodemailer');

Then after that, we create an object transporter:

var transporter = nodemailer.createTransport({
    service: 'gmail',
    auth: {
        user: 'youremail@gmail.com',
        pass: 'your password'
    }
});

This object will later be in charge of sending email.

Note the parameters given to the object transporter.

Please change the email address and password according to the email and password you have.

Next, we create objects mailOptions.

var mailOptions = {
    from: 'youremail@gmail.com',
    to: 'yourfriend@gmail.com',
    subject: 'Sending Email using Nodejs',
    text: 'That was easy!'
};

This object will accommodate the email data that we will send.

Like the origin address, destination address, subject, text, and attachments that will be sent.

Finally ...

We send the email with the function sendMail().

transporter.sendMail(mailOptions, (err, info) => {
    if (err) throw err;
    console.log('Email sent: ' + info.response);
});

Send Email Trial

Now try to execute the program ...

If you get an error like this:

This means, we failed to log in to the Gmail account.

There are several possibilities:

1. The password is wrong;
2. Security settings in Gmail that do not allow third party applications.
3. Internet connection;

Try checking again ...

For point number 2, try changing the security settings on your Google account.

Activate this section:

After a few minutes, try again ...

Send email successfully. 

To be sure, try checking the destination email inbox.

Send Advanced Email

Okay, we have successfully sent an email ...

However, there are a few more things we need to discuss:

Send Emails to Many People

To send e-mail to many people or recipients, we simply fill in the recipient's e-mail address in the property to at mailOptions: 1

var mailOptions = {
  from: 'youremail@gmail.com',
  to: 'myfriend@yahoo.com, myotherfriend@yahoo.com',
  subject: 'Sending Email using Node.js',
  text: 'That was easy!'
} 

Separate the recipient's address with a comma.

Send e-mail containing HTML

To send e-mail with HTML content, we only need the property to textbe html.

var mailOptions = {
  from: 'youremail@gmail.com',
  to: 'myfriend@yahoo.com',
  subject: 'Sending Email using Node.js',
  html: '<h1>Welcome</h1><p>That was easy!</p>'
}

Tip: We can also use HTML templates from external files. Use the module fsto read HTML files.

Try students in: Tutorial Nodejs # 5: Read Write Files with the File System Module

Sending Attachments

To send an attachment (attachment) , we can add the property attachmentson mailOptions.

The contents of the property attachmentsare an array of file objects to be attached.

Here is the code I got from the Nodemailer documentation. 2

let message = {
    ...
    attachments: [
        {   // utf-8 string as an attachment
            filename: 'text1.txt',
            content: 'hello world!'
        },
        {   // binary buffer as an attachment
            filename: 'text2.txt',
            content: new Buffer('hello world!','utf-8')
        },
        {   // file on disk as an attachment
            filename: 'text3.txt',
            path: '/path/to/file.txt' // stream this file
        },
        {   // filename and content type is derived from path
            path: '/path/to/file.txt'
        },
        {   // stream as an attachment
            filename: 'text4.txt',
            content: fs.createReadStream('file.txt')
        },
        {   // define custom content type for the attachment
            filename: 'text.bin',
            content: 'hello world!',
            contentType: 'text/plain'
        },
        {   // use URL as an attachment
            filename: 'license.txt',
            path: 'https://raw.github.com/nodemailer/nodemailer/master/LICENSE'
        },
        {   // encoded string as an attachment
            filename: 'text1.txt',
            content: 'aGVsbG8gd29ybGQh',
            encoding: 'base64'
        },
        {   // data uri as an attachment
            path: 'data:text/plain;base64,aGVsbG8gd29ybGQ='
        },
        {
            // use pregenerated MIME node
            raw: 'Content-Type: text/plain\r\n' +
                 'Content-Disposition: attachment;\r\n' +
                 '\r\n' +
                 'Hello world!'
        }
    ]
}

Let's try sending a file txtthat contains Hello World.

Here is the code:

var nodemailer = require('nodemailer');

var transporter = nodemailer.createTransport({
    service: 'gmail',
    auth: {
        user: 'youremail@gmail.com',
        pass: 'your password'
    }
});

var mailOptions = {
    from: 'youremail@gmail.com',
    to: 'yourfriend@gmail.com',
    subject: 'Sending Email using Nodejs',
    html: '<h1>Welcome</h1><p>That was easy!</p>',
    attachments: [
        {
            filename: 'text1.txt',
            content: 'hello world!'
        }
    ]
};

transporter.sendMail(mailOptions, (err, info) => {
    if (err) throw err;
    console.log('Email sent: ' + info.response);
});

Try execution:

The result:

Steady 

Bonus: Creating a Contact Form Application

Now, let's try sending emails for case studies in the real world.

Namely: create a contact form.

Please create a new file with the name contact_form.html as follows:

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Contact Us</title>

    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" integrity="sha384-MCw98/SFnGE8fJT3GXwEOngsV7Zt27NXFoaoApmYm81iuXoPkFOJwJ8ERdknLPMO"
        crossorigin="anonymous">
</head>

<body>
    <div class="container p-5">
        <div class="row justify-content-center">
            <div class="col-6">
                <h4 class="text-center my-4">Contact Us</h4>
                <div class="card">

                    <div class="card-body">
                        <form action="/contact/" method="POST">

                            <div class="form-group">
                                <label for="email">Email</label>
                                <input type="email" class="form-control" name="email" placeholder="email..." required />
                            </div>
                            <div class="form-group">
                                <label for="subject">Subject</label>
                                <input type="text" class="form-control" name="subject" placeholder="subject..."
                                    required />
                            </div>
                            <div class="form-group">
                                <label for="message">Message</label>
                                <textarea class="form-control" name="message" placeholder="your messages..." required></textarea>
                            </div>
                            <div class="form-group">
                                <input type="submit" class="btn btn-primary w-100" value="Send" />
                            </div>

                        </form>
                    </div>
                </div>
            </div>
        </div>
    </div>
</body>

</html>

In this HTML code, we use Bootstrap via the CDN. So that the display will look like this:

After creating the form, then make one more javascript file with the name app_contact.jsand contents as follows:

var http = require('http');
var fs = require('fs');
var qs = require('querystring');
var nodemailer = require('nodemailer');

http.createServer((req, res) => {

    if(req.url === "/") {
        // redirect ke halaman contact form
        res.writeHead(302, {
            'Location': '/contact/'
          });
        res.end();
    }

    // load the contact form
    if(req.url === "/contact/" && req.method === "GET"){
        fs.readFile("contact_form.html", (err, data) => {
            if (err) throw err;
            res.end(data);
        });
    }

    // send the email
    if(req.url === "/contact/" && req.method === "POST"){

        var requestBody = '';
        req.on('data', function(data) {
            // tangkap data dari form
            requestBody += data;

            // kirim balasan jika datanya terlalu besar
            if(requestBody.length > 1e7) {
              res.writeHead(413, 'Request Entity Too Large', {'Content-Type': 'text/html'});
              res.end('<!doctype html><html><head><title>413</title></head><body>413: Request Entity Too Large</body></html>');
            }
        });

        req.on('end', function() {
            let formData = qs.parse(requestBody);

            // send the email
            let transporter = nodemailer.createTransport({
                service: 'gmail',
                auth: {
                    user: 'youremail@gmail.com',
                    pass: 'your password'
                }
            });
            
            let mailOptions = {
                from: formData.email,
                replyTo: formData.email,
                to: 'contactemail@gmail.com',
                subject: formData.subject,
                text: formData.message
            };
            
            transporter.sendMail(mailOptions, (err, info) => {
                if (err) throw err;
                console.log('Email sent: ' + info.response);
                res.end("Thank you!");
            }); 
        });
               
    }

}).listen(8000);

console.log('server listening on http://localhost:8000/');

What you need to pay attention to in this code is in the section mailOptions:

let mailOptions = {
    from: formData.email,
    replyTo: formData.email,
    to: 'contactemail@gmail.com',
    subject: formData.subject,
    text: formData.message
};

The contents of the object formDataare data that we input from the form.

If you don't understand, please learn: Tutorial Nodejs # 7: How to Retrieve Data from Form

Properties replyToin mailOptionsfunction to specify email addresses that will be used to reply.

For more details, let's try ...

Then the email that will enter the inbox will be like this:

Email from contact form

Then, when we press the reply button , this e-mail will be returned to the e-mail that we gave to the property replyTo.

Reply to email from the concact form

 

Reference: https://www.petanikode.com/nodejs-email/