How to resolve "invalid_grant" error with nodemailer and gmail service?

Question

I am running a MERN stack application which sends email using Nodemailer and Gmail service. Email notifications are sent during API calls. The system has been live for 1 and a half years and they were never any issues with pushing email before. However, as of yesterday I have been trying to diagnose this issue. Here is the error message:

Transporter set up
[0] Error: invalid_grant
[0]     at D:\Dev\Projects\pro-optics\pro-optics\node_modules\nodemailer\lib\xoauth2\index.js:259:33
[0]     at PassThrough.<anonymous> (D:\Dev\Projects\pro-optics\pro-optics\node_modules\nodemailer\lib\xoauth2\index.js:328:20)
[0]     at Object.onceWrapper (events.js:312:28)
[0]     at PassThrough.emit (events.js:223:5)
[0]     at endReadableNT (_stream_readable.js:1185:12)
[0]     at processTicksAndRejections (internal/process/task_queues.js:81:21) {    
[0]   code: 'EAUTH',
[0]   command: 'AUTH XOAUTH2'
[0] \}

Here is the code associated with nodemailer and setting up the client and transporter:

const nodemailer = require('nodemailer');
const { google } = require('googleapis');

// Setting up OAuth2
const OAuth2 = google.auth.OAuth2;
const oauth2Client = new OAuth2(
  clientId,
  clientSecret,
  'https://developers.google.com/oauthplayground'
);

oauth2Client.setCredentials({
  refresh_token: refreshToken
});

let accessToken;

oauth2Client
  .refreshAccessToken()
  .then(tokens => (accessToken = tokens.credentials.access_token));

let transporter = nodemailer.createTransport({
  service: 'gmail',
  auth: {
    type: 'OAuth2',
    user,
    clientId,
    clientSecret,
    refreshToken,
    accessToken
  },
  tls: {
    rejectUnauthorized: false
  }
});

Here is the code for sending mail inside an API call:

// Prepare email
          const emailContent = getTicketTemplate(ticket, true, true);

          console.log('Transporter set up');

          let mailOptions = {
            from: `"Pro Optics" <${user}>`,
            to: recipients,
            subject: `[OFFICIAL] Ticket Report: INTV ${ticket._id} ✔`,
            html: emailContent
          };

          transporter
            .sendMail(mailOptions)
            .then(info => console.log(info))
            .catch(error => console.log(error));

I think it has something to do with Google rejecting access tokens but I'm not sure why this would happen so randomly.

This is a critical application and I would appreciate any help I can get on this.

Answer 1

考虑更新 id, secret, refresh token ，因为它帮助我解决了同样的问题。