How do I send bulk mails asynchronously in loop in node js?

I want to send multiple mails to users using asynchronously.

• user.js File

  var emailUtil = require("./emailUtil.js"); var userdata[100];

  // Suppose in userdata there are multiple data, let it be 100

  for(let i=0;i let emailBody = 'body of the mail', emailSubject = 'SGT Schedule'; emailUtil.sendEmail(emailBody, '' , emailSubject, '' , '' , user_data.email, 'Your Name', ''); }

In the other file where I write my email sending function

• emailUtil.js

  // Email Util File

  var nodemailer = require('nodemailer');
  
  // Not the movie transporter!
    var transporter = nodemailer.createTransport({
        service: 'gmail',
        auth: {
            user: 'email id', // Your email id
            pass: '*******' // Your password
        }
    });
  
  
  
  
      module.exports =
  
  {
  
     sendEmail: function sendMail(varhtml,vartext, 
          varsubject,varfrom, varfrom_name,varto, varto_name, 
        reply_to_email ) {
  
  
     //setup e-mail data with unicode symbols
     var mailOptions = {
  
         to: [varto], // list of receivers
         subject: varsubject, // Subject line
         text: vartext, // plaintext body
         html: varhtml // html body
     };
  
  
     console.log(mailOptions);
  
     // send mail with defined transport object
      transporter.sendMail(mailOptions, function (error, info) {
         if (error) {
             return console.log(error);
         }else{
           return console.log(info);
         }
     });
  
  

  } }

I want to send the response immediately. I don't need to wait for the emails So for doing that I am thinking about send mails using loop but asynchronously. Hope I am able to explain my question properly. Please let me know if there is any concern

via VIKAS KOHLI