It is not possible to send mail without authentication in Node Mailer.
But you can send mail using sendmail.In sendmail library does not need any smtp/auth to send email.
const sendmail = require('sendmail')();
sendmail({ from: 'test@finra.org', to: 'YOUR@gmail.com', subject: 'Hello World', html: 'Mail of test sendmail ' }, function (err, reply) { console.log(err && err.stack) console.dir(reply) })

Because, Node does not support SMTP natively afaik, so without using a library like node-mailer etc. you cannot send without using third party.
But you can send mail using sendmail.In sendmail library does not need any smtp/auth to send email.
const sendmail = require('sendmail')();
sendmail({ from: 'test@finra.org', to: 'YOUR@gmail.com', subject: 'Hello World', html: 'Mail of test sendmail ' }, function (err, reply) { console.log(err && err.stack) console.dir(reply) })