Send and Schedule e-mails from a Node.js app

As an application developer, how often we sense the need of a service that would send e-mails to specified or subscribed email ids? Even if there is no real need, we still fantasize about it while developing a pet-project or an app for fun, don't we 😁?

In this article, I am going to explain the simple steps to send emails from your node.js app. At the end of it, we will be able to schedule and send e-mails. Not only that, we will be creating a REST API to post required details to a node.js app for sending emails.

TL;DR
Here is the working app

REST API to send e-mail from a node.js app

You can find the code from my GitHub Repo: Test REST app for Sending e-mails

Setting the stage

Nodemailer is a super cool module for Node.js application to allow email sending so easily. Install it using npm

npm install nodemailer --save

Import Nodemailer in your .js(app.js, email.js whatever) file:

let nodemailer = require('nodemailer');

Next, follow these three simple steps to get things working:

• Setup a message option: This is to tell Nodemailer who is sending what message to whom?

 let mailOptions = {
        from: '<FROM_EMAIL_ADDRESS>',
        to: '<TO_EMAIL_ADDRESS>',
        subject: 'Email from Node-App: A Test Message!',
        text: 'Some content to send'
  };

👉 Note: The to property above can have multiple email ids separated by commas(,).

• Create a Nodemailer transporter using either SMTP(this is default) or some other transport mechanism

 let transporter = nodemailer.createTransport({
        service: 'gmail',
        auth: {
          user: '<FROM_EMAIL_ADDRESS>',
          pass: '<FROM_EMAIL_PASSWORD>'
        }
  });

👉 Note: In the above example, the service is mentioned as gmail. This is just an example. You can specify the name of the e-mail services you want to actually use.

• Use sendMail() method of your previously created transporter to deliver the message.

 transporter.sendMail(mailOptions, function(error, info){
        if (error) {
          console.log(error);
        } else {
          console.log('Email sent: ' + info.response);
        }
  });

That's all, you are done. Now we have everything required to send e-mail from this node.js app.

Hang on a Minute, We can schedule it!

Yeah, right! The real power of this app comes with the fact that, you will be able to schedule the emails like,

• Send now
• Send everyday at 7p.m.(19:00 hrs), like a daily-digest
• Send every 30 minutes.
• Send on 29th Feb!
• .... many many more desired ways.

You guessed it right, we need something like a cron job and for that we will be using a node module called, node-cron.

• First install it.

 node install node-cron --save

• Import node-cron and schedule a task

 let cron = require('node-cron');

 cron.schedule('* * * * *', () => {
     console.log('running a task every minute');
  });

👉 Note: You can read about several cron schedule patterns here. In the above example, we have scheduled a simple console log in every minute.

Here is the combined code where I am scheduling the e-mail to send every minute:

  let cron = require('node-cron');
  let nodemailer = require('nodemailer');

  // e-mail message options
  let mailOptions = {
        from: '<FROM_EMAIL_ADDRESS>',
        to: '<TO_EMAIL_ADDRESS>',
        subject: 'Email from Node-App: A Test Message!',
        text: 'Some content to send'
   };

  // e-mail transport configuration
  let transporter = nodemailer.createTransport({
        service: 'gmail',
        auth: {
          user: '<FROM_EMAIL_ADDRESS>',
          pass: '<FROM_EMAIL_PASSWORD>'
        }
    });

 cron.schedule('* * * * *', () => {
  // Send e-mail
  transporter.sendMail(mailOptions, function(error, info){
        if (error) {
          console.log(error);
        } else {
          console.log('Email sent: ' + info.response);
        }
    });
  });

TADAAA, Done!

REST API to Schedule and Send e-mail

Well, this is an optional part for you, if your are not interested in creating a REST API for the purpose of Scheduling and Sending e-mails. In case you mind, we can do it in a minute using sails.js. I have posted an article on How to Deploy your Sails.js app on Heroku and live longer. Take a quick look.

• Create a route in routes.js file of your sails.js app

  'post /api/sendemail': 'EmailController.sendEmail'

• Create an EmailController with sendEmail method. This method should have the code discussed above for scheduling and sending email.

Wow, that was quick, isn't it?

👉 Note: With sails.js, you can also use other cron libraries like sails-hook-cron as well. The details can be found here .

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Let me know if this was useful to you.

Please feel free to comment on the alternate ways and methods you may be using for serving the same purpose, i.e, Scheduling and Sending e-mails from a node.js ap.