How to add an email library in an existing nodejs server

I have a web server which is implemented using NodeJs. Now I want to add a functionality which will send a group of people email alerts if an event occurs. But I do not know how to add this feature in the existing code. I researched online and found sendgrid-nodejs but I do not know if that would work or not. I am not sure how to start. Please help.

You might want to check out nodemailer module.

The website has many different examples which you can follow.

Here is a one of those examples:

var nodemailer = require('nodemailer');
var transporter = nodemailer.createTransport();
transporter.sendMail({
  from: 'sender@address',
  to: 'receiver@address',
  subject: 'hello',
  text: 'hello world!'
});